1 Chapter 3. Elements, Atoms, Ions, and the Periodic Table The Periodic Law and the Periodic Table In the early 1800's many elements had been discovered and found to have different properties. In 1817 Döbreiner's triads with regularly varying properties: (Mg, Ca, Ba) (F, Cl, Br) and (S Se Te).1865: Newlands "law of octaves", about 55 elements: pattern of reactivity follows after 8 elements. However, no one had found a clear "order" in their properties until Mendeleev, Dmitri ( ) arranged 63 then known elements in the order of increasing atomic mass in a periodic table and showed some chemical properties would reappear periodically. In certain cases, he placed a lighter slightly heavier element before a lighter element so that the chemical properties of the vertical columns would be preserved. Even though in a different and much less clear form Meyer, Lothar ( ) also came up with a graph showing periodic properties similar to Medeleev. In Mendeleev's table, there was a gap. He purposely left blank position in his table so that the consistent vertical columns with the same chemical properties would be preserved. These missing elements were later discovered. The periodic law is an organized "map" of the elements that relates their structure to their chemical and physical properties. The periodic table is the result of the periodic law, and provides the basis for prediction of such properties as relative atomic and ionic size, ionization energy, and electron affinity, as well as metallic or non-metallic character and reactivity. The modern periodic table exists in several forms. The most important variation is in group numbering. The tables in the text use the two most commonly accepted numbering systems. Numbering Groups in the Periodic Table Periods and Groups Periods are the horizontal rows of elements in the periodic table; the columns represent groups or families. Elements in a vertical group have similar chemical properties. The vertical groups are currently named by numbers ranging from 1 to 18. An older way to identify the vertical groups is to use a Roman number and the capital letters A or B. Vertical groups of main group elements (or representative elements) were given a Roman numeral plus the letter A. Vertical groups of transition elements were given a Roman numeral plus the letter B. Representative elements are elements that always lose or gain the same number of electrons in chemical reactions. Transition elements are elements that can lose or gain variable numbers of electrons in chemical reactions. The lanthanide series and the actinide series are parts of periods 6 and 7, respectively, and groups that have been named include the alkali metals, the alkaline earth metals, the halogens, and the noble gases. Group A elements are called representative elements; Group B elements are transition elements. Metals, metalloids, and nonmetals can be identified by their location on the periodic table.
2 These groups are number from 1-18, left to right and groups have their Roman numbers and A or B classification.. Name Elements Common Valence Electron Configuration Group 1 (IA) - Alkali metal: Li, Na, K Rb, Cs, Fr ns 1 Group 2 (IIA) - Alkaline earth metals: Be, Mg, Ca, Sr, Ba, Ra ns 2 Group 13 (IIIA) - No specific name B, Al, Ga, In, Tl ns 2 3p 1 Group 14 (IVA) - No specific name C, Si, Ge, Sn, Pb ns 2 3p 2 Group 15 (VA) - No specific name N, P, As, Sb, Bi ns 2 np 3 Group 16 (VIA) - No specific name O, S, Se, Te, Po ns 2 np 4 Group 17 (VIIA) - Halogens: Cl, Br, I, At ns 2 np 5 Group 18 (VIIIA) - Noble gases: He, Ne, Ar, Kr, Xe, Rn ns 2 np 6 In addition to groups in the periodic table there are three blocks of elements called transition elements (which are labeled with B), Lanthanides and Actinides ( placed bottom of the table. Metals, Nonmetals and Metalloids Most of the elements in the periodic table are metals. Note the stair step line in the periodic table. Elements to the left of the line are metals. Elements to the right of the line are nonmetals. In between metal and non-metals there are semi-metals or metalloids. Metals lose electrons and nonmetals gain electrons. Ionic Compounds are formed when electrons are exchanged in this way between metals and nonmetals. Covalent or Molecular Compounds are formed between non metals and non metals react by sharing electrons. Atomic Number and Atomic Mass The atomic number (Z) of an element represents the number of protons in the nucleus of atoms of that specific element. No two element has that same number of protons. Atomic number after it was discovered proved to be the best order without any discrepancies to arrange the elements in the periodic table and is shown on top of the space for each element. The atomic number will always be a whole number value without decimals. At the bottom average atomic mass calculated based on isotopes of each elements is written.
3 Problem: Pick the a) representative elements, b) transition elements, c) inert gas elements, d) elements that from anions, e) semi- metals, and f) elements that from cations from the following list: Ca, Si, K, Ar, Cu, Fe Zn, Ge, Kr, Cl, O, F. Answer: a) representative elements: Ca, Cl, O, F b) transition elements: Cu, Fe c) inert gas elements: Ar, Kr d) elements that from anions: O, F e) semi- metals: Si, Ge f) elements that from cations: Ca, K, Cu, Fe Zn Look on a periodic chart at the elements listed below. Do you know how to find an elements atomic number? Problem: Use your periodic table to find the symbol, atomic number and atomic mass rounded to two decimal place of each of the following elements: a) Magnesium b) Neon c) Selenium d) Gold Answer Mg, atomic number = 12, mass = amu
4 Ne, atomic number = 10, mass = amu Se, atomic number = 34, mass amu Au, atomic number 79, mass amu Electron Arrangement and the Periodic Table Bohr concluded that the energy levels of an atom can handle only a certain number of electrons at a time. The Quantum Mechanical Atom J. J. Thomson had demonstrated the particle properties of the electron earlier. Because electrons can exhibit diffraction patterns, they have a dual nature of both wave and particle. In 1924, Louis de Broglie suggested that the electron should have wave properties. Light waves exhibit "diffraction." Erwin Schrodinger developed equations to describe the regions around the nucleus where electrons had the probability of being 95% of the time. These regions of high probability for finding an electron around the nucleus were called orbitals. Three dimensional models of the probability regions or orbitals can be constructed. Electron cloud representations are used to show the space that can be occupied by electrons in different energy levels. Building Atoms by Orbital Filling Schrodinger's work showed that each orbital could have a maximum of two electrons. Energy levels could contain different numbers of orbitals. Energy levels further from the nucleus can accommodate more orbitals than energy levels nearer the nucleus. Energy levels can have sublevels when multiple orbitals are present. Orbital Shapes Sub-level Shape # of orbitals/energy level Picture s spherical 1 p dumbbell 3 d complex 5 f very complex 7
5 Energy Levels n=1 n=2 n=3 n=4 number of sublevels one two three four Sublevel Names s s and p s, p and d s. p, d and f Sublevels and orbitals 1s (1) 2s(1) 2p(3) 3s(1) 3p(3) 3d(5) 4s(1) 4p(3) 4d(5) 4f(7) Number orbitals maximum number of electrons per sublevel 2(2n 2 ) 2 + 6= 9(2n 2 ) = 18 (2n 2 ) = 32 (2n 2 ) The maximum number of electrons that can be in an energy level is 2n 2, where n is equal to the energy level being considered. Energy Level maximum number of electrons in an Energy Level # of sublevels Sublevels names n = s 2 n = s, p 2, 6 =8 n = s, p, d 2, 6, 10 =18 n = s, p, d, f 2, 6, 10, 14 =32 Problem: How many electrons are found: Within principle shells? a) n = 1 b) n = 2 c) n = 3 d) n =4 e) n = 5 Answer: a. n = 1; 2n 2 = 2(1) 2 = 2 b. n = 2; 2n 2 = 2(2) 2 = 8 c. n = 3; 2n 2 = 2(3) 2 = 18 d. n = 4; 2n 2 = 2(4) 2 = 32 e. n = 5; 2n 2 = 2(5) 2 = 50 Problem: With in a sub-shells: a) s, b) p c) d, d) f Answer: a) s = 2, b) p=6 c) d=10, d) f= 14 maximum number of electrons per sublevel Problem: With in a Orbital? Answer: Two electrons. Energy Levels and Sublevels A sublevel is a part of a principal energy level and is designated s, p, d, and f. Each sublevel may contain one or more orbitals, regions of space containing a maximum of two electrons with their spins paired. Schrodinger's work showed that Eeach orbital could have a maximum of two electrons. Energy levels could contain different numbers of orbitals. Energy levels further from the nucleus can accommodate more orbitals than energy levels nearer the nucleus.
6 Energy levels can have sublevels when multiple orbitals are present. Building Atoms by Orbital Filling Amazingly, the "electron configurations" of the elements are "embedded" in the Periodic Table. Honk, if you can see this "embedded" information in the Periodic Table? Analogy: The periodic table is actually a packing slip that tells how the electrons are packed around the nucleus. Electronic Configuration - the arrangement of electrons, in orbits or orbitals, around a nucleus of an atom. Electron Configuration and the Aufbau ( Building Up) Principle A scheme used by chemist to obtain electronic configuration of a multi-electron atom in the ground state by filling atomic orbital starting with lowest energy. 1s 2s 2p3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d (building up principle) If two or more orbitals exist at the same energy level, they are degenerate. Do not pair the electrons until you have to.
7 Problem: What is the electron configuration of a) K and b) P? Answer: Using Aufbau principle or periodic table a. Potassium: 1s 2, 2s 2, 2p 6, 3s 2, 3p 6, 4s 1 b. Phosphorus: 1s 2, 2s 2, 2p 6, 3s 2, 3p 3 Problem: Examine the electron configurations below, and name the element. 1s 2 2s 2 1s 2 2s 2 2p 3 1s 2 2s 2 2p 6 3s 2 3p 1 Answer: Going through the periodic table. 1s 2 2s 2 (He) 1s 2 2s 2 2p 3 (N) 1s 2 2s 2 2p 6 3s 2 3p 1 (Al) Problem: If a neutral atom in its ground state contains only 5 electrons in its outermost p sublevel, it is an atom in what "vertical group" of elements? Answer: group 17 or VIIB or Halogen family. Problem: If a neutral atom in its ground state contains 2 electrons in its outermost s sublevel, it is an atom in what "vertical group" of elements? Answer: group 2 or IIA or Alkaline Earth family. Problem: State what is similar and what is different about the electron configuration of fluorine and chlorine. Answer: F: 1s 2 2s 2 2p 5 Cl: 1s 2 2s 2 2p 6 3s 2 3p 5 valance shell electron configuration is similar but electron configurations are different. Problem: Fluorine and chlorine have similar chemical properties. Oxygen and sulfur have similar chemical properties. However, oxygen and sulfur have chemical properties different from fluorine and chlorine. What does electron configuration have to do with this observation? Answer: F: 1s 2 2s 2 2p 5 Cl: 1s 2 2s 2 2p 6 3s 2 3p 5 both have same vala.nce electron configurations and similar chemical properties. O: 1s 2 2s 2 2p 4 S: 1s 2 2s 2 2p 6 3s 2 3p 4 both have same valance electron configurations and similar chemical properties.. However, two groups F, Cl: ns 2 np 5 and O, S: ns 2 np 4 have different valance electron configurations creating different chemical properties. Valence Electrons The outermost electrons in an atom are valence electrons. For representative elements, the number of valence electrons in an atom corresponds to the group or family number. If atoms of different elements have the same electron arrangement in their valence shell electrons, then they can have similar chemical properties even if their atomic numbers or atomic masses are quite different. Metals tend to have fewer valence electrons than nonmetals. Valence electrons are involved in chemical interactions and bonding (valence comes from the Latin valere, "to be strong"). Valence shell electrons are available to be lost, gained, or shared in chemical reactions. Problem: How many total electrons and valance electrons are in the following atoms: a) K, b) F, c) P, d) O and e) Ca Answer For counting valance electrons go to the period the element is found and count ( excluding transition element blocks) from left to right until element is found. a. Total electrons = 19 (same as atomic number), valence electrons = 1 b. Total electrons = 9 (same as atomic number), valence electrons = 7 c. Total electrons = 15 (same as atomic number), valence electrons = 5 d. Total electrons = 8 (same as atomic number), valence electrons = 6
8 e. Total electrons = 20 (same as atomic number), valence electrons = 2 Abbreviated Electron Configurations Abbreviated electronic configuration is separating valance electrons from core electrons and designating core electrons as a noble gas. E.g. What is the abbreviated electron configurations of a) K, b) P and Sn? Answer First, obtain the electron configuration then find the valence electrons. a. Potassium (K): 1s 2, 2s 2, 2p 6, 3s 2, 3p 6, 4s 1 b. Phosphorus (P): 1s 2, 2s 2, 2p 6, 3s 2, 3p 3 c. Tin (Sn): 1s 2, 2s 2, 2p 6, 3s 2, 3p 6, 4s 2, 3d 10, 4p 6, 5s 2, 4d 10, 5p 2 Second, lump all non valance electrons as core abbreviated as a noble gas con figuration. a. Ar: 1s 2, 2s 2, 2p 6, 3s 2, 3p 6 = [Ar] b. Ne: 1s 2, 2s 2, 2p 6, 3s 2 = [Ne] c. Kr: 1s 2, 2s 2, 2p 6, 3s 2, 3p 6, 4s 2, 3d 10, 4p 6 = [Kr] Final answer a. Potassium (K): [Ar] 4s 1 b. Phosphorous (P): [Ne] 3s 2, 3p 3 c. Tin (Sn): [Kr] 5s 2, 4d 10, 5p 2 Electron configuration of the elements is predictable, using the Aufbau Principle. Knowing the electron configuration, we can identify valence electrons and begin to predict the kinds of reactions that the elements will undergo. Elements in the last family, the noble gases, have either two or eight valence electrons. Their most important properties are their extreme stability and lack of reactivity. A full energy level is responsible for this unique stability. The Octet Rule Noble gases are non-reactive because they all have a complete outer shell. An atom chemically reacts to fill its valance shell. A full valance shell contains eight electrons there fore the name octet. The octet rule tells us that in chemical reactions atoms of elements will gain, lose or share the minimum number of electrons necessary to achieve the electron configuration of the nearest noble gas. octet rule - the rule which predicts that atoms form the most stable molecules or ions when they are surrounded by eight electrons in their highest occupied energy (valance) level. Electronic configuration of ions Series of negative ions, noble gas atom, and positive ions with the same number electrons and electronic configuration. Electron configuration of ions is obtained by adding more electrons (anions) or removing electrons (cations) from a neutral atom. In the process atoms achieves a noble gas electron configuration. Group 1 (or IA), Alkali Metals have one valence electron. They all form +1 cations when the single valence electron is lost. Metals lose electrons and achieve electron configuration of preceding noble gas. E.g. Potassium (K): K K + (cation) + e - Oxygen (O):
9 O + 2e - O 2- (anion) Metallic elements tend to form cations and nonmetals form anions that are isoelectronic with their nearest noble gas neighbor. Isoelectronic electronic configurations If atom and a cation or anion have same number of electrons they are called isoelectronic. E.g. K + and Ar O 2- and Ne Problem: Which of the following are isoelectronic: F,Cl, K +, Ar Answer: a. F, 10e ; Cl, 18 e ; Not isoelectronic b. K +, 18 e ; Ar, 18e ; Isoelectronic Ion Formation and the Octet Rule Metals lose electrons and achieve a an octet of valance electrons similar to electron configuration of preceding noble gas. E.g. Potassium (K): [Ar] 4s 1 K ([Ar] 4s 1 ) K + ([Ar]) + e - Oxygen (O): [He] 2s 2 2p 4 O ([He] 2s 2 2p 4 ) + 2e - O 2- ([Ne]) a. I (54 e ) = Xe= 1s 2, 2s 2, 2p 6, 3s 2, 3p 6, 4s 2, 3d 10, 4p 6, 5s 2, 4d 10, 5p 6 b. Ba 2+ (54 e )= Xe= 1s 2, 2s 2, 2p 6, 3s 2, 3p 6, 4s 2, 3d 10, 4p 6, 5s 2, 4d 10, 5p 6 c. Se 2 (36 e ) =Kr = 1s 2, 2s 2, 2p 6, 3s 2, 3p 6, 4s 2, 3d 10, 4p 6 d. Al 3+ (10 e )=Ne = 1s 2, 2s 2, 2p 6 Trends in the Periodic Table Atomic Size Atomic size increases from top to bottom but decreases from left to right in the periodic table. Cations are smaller than the parent atom. Anions are larger than the parent atom. Ions with multiple positive charge are even smaller than their corresponding monopositive ion; ions with multiple negative charge are larger than their corresponding less negative ion. Problem: Arrange the following list of elements in order of increasing atomic size. a) Al, Si, P, Cl, S b) In, Ga, Al, B, Tl c) Sr, Ca, Ba, Mg, Be d) O,N, Sb, Bi, As Answer: a. (Smallest) Cl, S, P, Si, Al (Largest) b. (Smallest) B, Al, Ga, In, Tl ( Largest) c. (Smallest) Be, Mg, Ca, Sr, Ba (Largest) d. (Smallest) N, P, As, Sb, Bi (Largest) Ionization Energy The energy required to remove an electron from an atom in the gas phase.
10 The energy required to remove an electron from the atom is the ionization energy. Descending a group, the ionization energy decreases. Proceeding across a period, the ionization energy increases. Problem: Arrange the following list of elements in order of increasing ionization energy. a) N,F, O b) Li, K, Cs c) Br, I, Cl Answer: a) (Smallest) N, O, F(Largest) b) (Smallest) Cs, K, Li (largest) d) (Smallest) Cl, Br, I (Largest) Electron Affinity The energy released when a single electron is added to neutral atom in the gaseous state is known as the electron affinity. Electron affinities generally decrease proceeding down a group and increase proceeding across a period. Exceptions exist for periodic trends. They are generally small anomalies, and do not detract from the predictive power of the periodic table. Problem: Arrange the following list of elements in order of increasing ionization energy. a. Na, Li, K b. Br, F, Cl c. S, O, Se Answer: a. (Smallest) Li, Na, K (Largest) b. (Smallest) F, Br, Cl (Largest) c. (Smallest) Se, S, O (Largest) Ion Size Ions follows same trends as for atomic radius in a group, fro example taking oxide and sulfide ion: radius of O 2- < S 2-. Cation or positive ions have fewer electrons than neutral atom and nuclear charge being same attract remaining electrons strongly making cation smaller than the neutral atom Anions or negative ions larger than neutral atom. Anions are larger than the atoms from which there are formed. Adding electrons to an atom increases the repulsion between electrons. Anion has a harder time holding on to the electrons.
11 CHEM 120 Homework 3. Chapter 3 1. In the modern periodic table, the elements are arranged according to increasing. a. atomic masses b. number of neutrons c. atomic number d. mass number 2. How many periods are found on the periodic table? a. 2 b. 7 c. 18 d Which period contains the element Cesium? a. 2 b. 4 c. 6 d Where are the alkaline earth metals located on the periodic table? a. Group 1 (IA) b. Group 2 (IIA) c. Group 13 (IIIA) d. Group 14 (IVA) e. Group 17 (VIIA) 5. Which one of the following is not a representative element a. Na b. As c. Ca d. Fe e. Cl 6. How many orbitals are in an s sublevel? How many in a p sublevel? a. 2;6 b. 1;1 c. 1; 3 d. 3; 5 7. Which of the following correctly gives the electron capacity of a principal energy level in terms of the number n? a. n b. 2n c. 2n + 2 d. n 2 e. 2n 2 7. What requirement must be met in order for two electrons to coexist in the same orbital? a. they go to a s orbital b. they go to a p orbital c. they must have opposite spins d. they must have parallel spins 8. How many valence electrons are present in an atom of silicon? a. 2 b. 3 c. 4 d. 5 e The electronic configuration in an atom of argon, a. 1s 2 2s 2 b. 1s 2 2s 2 2p 6 c. 1s 2 2s 2 2p 6 3s 2 3p 6 d. 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p Common valence electron configuration of halogens a. ns 1 b. ns 2 c. ns 2 3p 2 d. ns 2 np 3 e. ns 2 np What is not isoelectronic with K +? a. S 2- b. Ar c. Cl - d. Na + e. Ca Which of the following atoms has the biggest size (radius)? a. Na b. Al c. Cl d. Rb e. I 13. Which of the following elements has the highest ionization energy? a. Li b. B c. O d. F e. Ne 14. Which one of the following elements has the highest electron affinity? a. Li b. K c. Kr d. O e. Cl 15. What charge is found on a ion from Al? a. +1 b. -2 c. +3 d. -3
12 Sample Test Chapter 3 1. Which two scientists in 1869 arranged the elements in order of increasing atomic masses to form a precursor of the modern periodic table of elements? Ans. Mendeleev and Meyer 2. Who stated that the elements, when arranged according to their atomic masses, showed a distinct periodicity of their properties? Ans. Dimitri Mendeleev 3. In the modern periodic table, the elements are arranged according to what system? Ans. increasing atomic number 4. The modern periodic law states that the physical and chemical properties of the elements are periodic functions of what property? Ans. atomic number 5. What do we call the horizontal row of elements on the periodic table? Ans. periods 6. How many periods are found on the periodic table? Ans. seven 7. Which period contains the element sodium? Ans. three 8. What do we call the columns of elements on the periodic table? Ans. groups 9. What number for an atom gives the number of electrons and protons found in that atom? Ans. atomic number 10. Where are the alkaline earth metals located on the periodic table? Ans. Group IIA (2) 11. What is the general name given to the elements of Group VIIA (17)? Ans. Halogens 12. What term is used for the elements straddling the "staircase" boundary between the metals and nonmetals? Ans. Metalloids or semi-metals 13. For a representative element, how can we deduce the number of valence electrons in a neutral atom from the position of the element in the Periodic Table? Ans. the group number (Roman numbers with Bs) is also the number of valence electrons 14. How many orbitals are in an s sublevel? How many in a p sublevel? Ans, 1; In what way(s) are the three orbitals in the 2p sublevel similar; in what way(s) are they different? Ans. they have the same shape and the same energy; they are oriented differently in space 16. What requirement must be met in order for two electrons to coexist in the same orbital? Ans. they must have opposite spins 17. State the Aufbau Principle. Ans. Electrons occupy the available orbital of lowest energy first. 18. How many electrons are present in an atom of silicon? Ans. Fourteen 19. Give the electronic configuration in an atom of argon, element number 18. Ans. 1s22s22p63s23p6 20. Give the electronic arrangement in an atom of strontium, element number 38. Ans. 1s22s22p63s23p64s23d104p65s2 21. How many electrons are present in a chloride ion? Ans. Eighteen 22. State the Octet Rule. Ans. Elements tend to react in such a way as to attain the electron configuration of the atoms of the noble gas nearest to them in the Periodic Table 23. Give the name of a Group IA (1) ion that has the following electronic arrangement: 1s 2 2s 2 2p 6 Ans. sodium ion 24. Give the name of a VIIA (17) ion that has the following electronic arrangement: 1s22s22p63s23p6 Ans. chloride 25. What ion carries a 2- charge and is isoelectronic with K +?
13 Ans. S Give the complete electronic arrangement of a sulfide ion, S 2-. Ans. 1s22s22p63s23p6 27. Atoms with the biggest radii occur in the region of the Periodic Table. Ans. bottom left 28. How would you expect an Al 3+ ion to compare in size with an Al atom? Explain why? Ans. The ion will be much smaller. In forming the ion, the atom loses all its outermost electrons. The net positive charge on the ion ensures that all the electrons in the ion are strongly attracted to the nucleus, keeping the ion small. 29. Which group of elements has the highest ionization energies? Which group has the lowest? Ans. Group VIIIA (18) are highest; Group IA (1) are the lowest. 30. Explain what is meant by electron affinity. Ans. It is the energy released when a neutral atom gains an electron to form an anion. 31. In Mendeleev's table of the elements, they were arranged according to A. atomic number B. mass number C. atomic mass D. neutron number E. density Ans. C. atomic mass 32. The modern periodic table is arranged according to what property? A. atomic number B. mass number C. atomic mass D. neutron number E. density Ans. A. atomic number 33. What do we call a complete horizontal row of elements on the periodic table? A. group B. period C. family D. representative elements E. transition elements Ans, B 34. What are all the elements in the A-groups often called? A. transition elements B. lanthanides C. metals D. non-metals E. representative elements Ans. E 35. Which of the following elements is a metalloid? A. C B. Ge C. Pb D. N E. P Ans. B 36. Where are the alkali metals located on the periodic table? A. representative elements B. transition metals C. Group IA (1) D. Group IIA (2) E. Group IIIA (3) Ans. C 37. How many valence electrons are in an atom of carbon? A.8 B. 6 C. 4 D. 1 E. 0 Ans. C 38. What is the lowest energy sublevel of a principal level? A. d B. e C. f D. s E. p Ans. D 39. How many sublevels are there in the third principal energy level? A. 3 B. 2 C. 1 D. 0 E. 4 Ans. A 40. How many orbitals are there in a p sublevel? A. 2 B. 3 C. 1 D. 0 E. 4 Ans. B 41. Which of the following correctly gives the electron capacity of a principal energy level in terms of the number n? A. n B. 2n C. 2n + 2 D. n 2 E. 2n 2 Ans. E 42. What is the electron configuration of sulfur, atomic number 16? A. 1s 2 1p 6 2s 2 2p 6 B. 1s22s22p62d6 C. 1s22s22p63s23p4 D. 1s22s22p63s23d4 E. 1s22s22p63s22d4 Ans. C 43. Which one of the following electron configurations is appropriate for a normal atom? A. 1s12s1 B. 1s22s1 C. 1s22s22p8 D. 1s22s22p43s1 E. 1s22s22p63d1 Ans. B
14 44. Which of the following elements is most likely to form a 3+ ion? A. Li B. K C. Al D. N E. Cu Ans. C 45. Give the complete electronic configuration of a sodium ion. A. 1s22s22p5 B. 1s22s22p6 C. 1s22s22p63s1 D. 1s22s22p63s2 E. 1s22s22p63s23p64s1 Ans. B 46. Which of the following ions does not follow the octet rule? A. Na+ B. Ca2+ C. Al3+ D. N3- E. Cl2- Ans. E 47. Which of the following atoms has the biggest size (radius)? A. Na B. Al C. Cl D. Rb E. I Ans. D 48. Which of the following elements has the highest ionization energy? A. Li B. B C. O D. F E. Ne Ans. E 49. Which of the following elements has the lowest ionization energy? A. Li B. B C. O D. F E. Ne Ans. A 50. The electron affinity is A. the energy required to remove an electron from an isolated atom B. the force between two electrons in the same orbital C. the force between two ions of opposite charge D. the energy released when an isolated atom gains an electron E. the attraction of an atom for an electron in a chemical bond Ans. D 51. Which one of the following elements has the highest electron affinity? A. Li B. K C. Kr D. O E. Cl Ans. E 52. T F In Mendeleev's table, the elements were arranged according to their atomic numbers. Ans. F 53. T F There are nine periods on the periodic table. Ans. F 54. T F Sulfur (S) is one of the representative elements. Ans. T 55. T F Platinum (Pt) is a lanthanide element. Ans. F 56. T F Tin (Sn) is a metalloid. Ans. F 57. T F Valence electrons are involved when atoms form bonds. Ans. T 58. T F There are a maximum of 50 electrons in principal energy level number five. Ans. T 59. T F Atoms of the noble gas elements, Group VIII A (18), do not form bonds with any other elements. Ans. F 60. T F There are eight valence electrons in a chloride ion. Ans. F 61. T F The ions formed from Group IIA (2) atoms have charges of 2+. Ans. T 62. T F Cations tend to be formed from metal atoms, while anions are formed from non-metal atoms. Ans. T 63. T F The atoms of smallest radius are those of elements in top left hand part of the periodic table. Ans. F 64. T F The halogens (Group VII A (17)) have the lowest ionization energies of any group in the periodic table.
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47374_04_p25-32.qxd 2/9/07 7:50 AM Page 25 4 Atoms and Elements 4.1 a. Cu b. Si c. K d. N e. Fe f. Ba g. Pb h. Sr 4.2 a. O b. Li c. S d. Al e. H f. Ne g. Sn h. Au 4.3 a. carbon b. chlorine c. iodine d.
5.4 Trends in the Periodic Table Think about all the things that change over time or in a predictable way. For example, the size of the computer has continually decreased over time. You may become more
Periodic Table Trends in Element Properties Ron Robertson r2 n:\files\courses\1110-20\2010 possible slides for web\ch9trans2.doc The Periodic Table Quick Historical Review Mendeleev in 1850 put together
Unit 1 The Periodic Table: Periodic trends There are over one hundred different chemical elements. Some of these elements are familiar to you such as hydrogen, oxygen, nitrogen and carbon. Each one has
The Periodic Table Horizontal Rows are called Periods. Elements in the same period have the same number of energy levels for ground state electron configurations. Vertical Rows are called Families or Groups.
179 ELECTRON CONFIGURATION (SHORT FORM) - We can represent the electron configuration without drawing a diagram or writing down pages of quantum numbers every time. We write the "electron configuration".
Name: Date: 1. Which of the following best describes an atom? A. protons and electrons grouped together in a random pattern B. protons and electrons grouped together in an alternating pattern C. a core
Electron Configurations, Isoelectronic Elements, & Ionization Reactions Chemistry 11 Note: Of the 3 subatomic particles, the electron plays the greatest role in determining the physical and chemical properties
Trends of the Periodic Table Diary Trends are patterns of behaviors that atoms on the periodic table of elements follow. Trends hold true most of the time, but there are exceptions, or blips, where the
CHAPTER 3 1. Which combination of individual and contribution is not correct? a. Antoine Lavoisier - clarified confusion over cause of burning b. John Dalton - proposed atomic theory c. Marie Curie - discovered
Noble gases Period alogens Alkaline earth metals Alkali metals TRENDS IN TE PERIDI TABLE Usual charge +1 + +3-3 - -1 Number of Valence e - s 1 3 4 5 6 7 Electron dot diagram X X X X X X X X X 8 Group 1
Chemistry 101 ANSWER KEY REVIEW QUESTIONS Chapter 8 Use only a periodic table to answer the following questions. 1. Write complete electron configuration for each of the following elements: a) Aluminum
Chemistry CP Unit 2 Atomic Structure and Electron Learning Targets (Your exam at the end of Unit 2 will assess the following:) 2. Atomic Structure and Electron 2-1. Give the one main contribution to the
Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 7 John D. Bookstaver St. Charles Community College Cottleville, MO Development of Table
The Advanced Placement Examination in Chemistry Part I Multiple Choice Questions Part II Free Response Questions Selected Questions from1970 to 2010 Atomic Theory and Periodicity Part I 1984 1. Which of
Name: ate: 1. In the modern, the elements are arranged in order of increasing. atomic number. mass number. oxidation number. valence number 5. s the elements in Group I are considered in order of increasing
AP Chem Summer Assignment Worksheet #1 Atomic Structure 1. a) For the ion 39 K +, state how many electrons, how many protons, and how many 19 neutrons are present? b) Which of these particles has the smallest
7.4 Using the Bohr Theory LEARNING TIP Models such as Figures 1 to 4, on pages 218 and 219, help you visualize scientific explanations. As you examine Figures 1 to 4, look back and forth between the diagrams
Unit 3.2: The Periodic Table and Periodic Trends Notes The Organization of the Periodic Table Dmitri Mendeleev was the first to organize the elements by their periodic properties. In 1871 he arranged the
The Periodic Table; Chapter 5: Section 1 - History of the Periodic Table Objectives: Explain the roles of Mendeleev and Moseley in the development of the periodic table. Describe the modern periodic table.
Introductory Chemistry: A Foundation FOURTH EDITION by Steven S. Zumdahl University of Illinois Elements, Atoms & Ions Chapter 4 1 2 Elements Aims: To learn about the relative abundances of the elements,
Atomic Theory: History of the Atom Atomic Theory: experimental observations that led scientists to postulate the existence of the atom (smallest bit of an element). 1. Law of Conservation of Mass -During
Unit 2 Periodic Behavior and Ionic Bonding 6.1 Organizing the Elements I. The Periodic Law A. The physical and chemical properties of the elements are periodic functions of their atomic numbers B. Elements
Objectives 1. To learn about the shapes of the s, p and d orbitals 2. To review the energy levels and orbitals of the wave mechanical model of the atom 3. To learn about electron spin A. Electron Location
Trends of the Periodic Table Basics Trends are patterns of behaviors that atoms on the periodic table of elements follow. Trends hold true most of the time, but there are exceptions, or blips, where the
Name 1. What is the term for the weighted average mass of all the naturally occurring isotopes of an element? ans: atomic mass 2. Which is exactly equal to 1/12 the mass of a carbon -12 atom? ans: atomic
Ions & Their Charges Worksheet Name Date Teacher Diagram of charges based on groups on the periodic table including transition metals and noble gases: IA IIA Transition IIIA IVA VA VIA VIIA VIIIA metals
PERIODIC TABLE OF THE ELEMENTS Periodic Table: an arrangement of elements in horizontal rows (Periods) and vertical columns (Groups) exhibits periodic repetition of properties First Periodic Table: discovered
Atoms, Elements, and the Periodic Table (Chapter 2) Atomic Structure 1. Historical View - Dalton's Atomic Theory Based on empirical observations, formulated as Laws of: Conservation of Mass Definite Proportions
Chapter 8 Basic Concepts of the Chemical Bonding 1. There are paired and unpaired electrons in the Lewis symbol for a phosphorus atom. (a). 4, 2 (b). 2, 4 (c). 4, 3 (d). 2, 3 Explanation: Read the question
THE PERIODIC TABLE O F T H E E L E M E N T S The Academic Support Center @ Daytona State College (Science 117, Page 1 of 27) THE PERIODIC TABLE In 1872, Dmitri Mendeleev created the periodic table arranged
P. Table & E Configuration Practice TEST Multiple Choice Identify the choice that best completes the statement or answers the question. 1. A line spectrum is produced when an electron moves from one energy
Department of Physics and Geology The Elements and the Periodic Table Physical Science 1422 Equipment Needed Qty Periodic Table 1 Part 1: Background In 1869 a Russian chemistry professor named Dmitri Mendeleev
Chapter 8 Electron Configurations Page 1 Chapter 8 Atomic Electronic Configurations and Periodicity 8-1. Substances that are weakly attracted to a magnetic field but lose their magnetism when removed from
CHEM 10113, Quiz 2 September 7, 2011 Name (please print) All answers must use the correct number of significant figures, and must show units! IA Periodic Table of the Elements VIIIA (1) (18) 1 2 1 H IIA
reflect Suppose you wanted to organize your locker at school. How could you separate and arrange everything in an organized way? You could place the books, notebooks, and folders on a shelf that is separate
Name: Teacher s Name: Class: Block: Date: Unit 3 Study Guide: Electron Configuration & The Periodic Table 1. For each of the following elements, state whether the element is radioactive, synthetic or both.
Part I: Principal Energy Levels and Sublevels As you already know, all atoms are made of subatomic particles, including protons, neutrons, and electrons. Positive protons and neutral neutrons are found
. ATOMIC STRUCTURE FUNDAMENTALS LEARNING OBJECTIVES To review the basics concepts of atomic structure that have direct relevance to the fundamental concepts of organic chemistry. This material is essential
CHAPTER REVIEW EVIEW ANSWERS 1. alkaline-earth metals 2. halogens 3. metals. electron affinity 5. actinides 6. answers should involve the transmutation of one element to another by a change in the number
ATOMS AND THE PERIODIC TABLE CHAPTER 3 PHYSICAL SCIENCE Chapter 3 Vocabulary Words (27 words) Nucleus Atomic number Proton Mass number Neutron Isotopes Electron Atomic mass unit (amu) Energy level Average
Electrons In Atoms Mr. O Brien (SFHS) Chapter 5 Standard 1D Electrons in Atoms (std.1d) What are Bohr Models? planetary model in which the negatively-charged electrons orbit a small, positively-charged
Molecular Models & Lewis Dot Structures Objectives: 1. Draw Lewis structures for atoms, ions and simple molecules. 2. Use Lewis structures as a guide to construct three-dimensional models of small molecules.
Ionic and Metallic Bonding BNDING AND INTERACTINS 71 Ions For students using the Foundation edition, assign problems 1, 3 5, 7 12, 14, 15, 18 20 Essential Understanding Ions form when atoms gain or lose
Basic Chemistry Why do we study chemistry in a biology course? All living organisms are composed of chemicals. To understand life, we must understand the structure, function, and properties of the chemicals
KEY Honors Chemistry Assignment Sheet- Unit 3 Extra Learning Objectives (beyond regular chem.): 1. Related to electron configurations: a. Be able to write orbital notations for s, p, & d block elements.
Selected Honour Chemistry Assignment Answers pg. 9 Unit 3: Quantum Theory, Periodicity and Chemical Bonding Chapter 7: The Electronic Structure of Atoms (pg. 240 to 241) 48. The shape of an s-orbital is
APS Science Curriculum Unit Planner Grade Level/Subject Chemistry Stage 1: Desired Results Enduring Understanding Topic 1: Elements and the Periodic Table: The placement of elements on the periodic table
2.21 Ionic Bonding 100% ionic compounds do not exist but predominantly ionic compounds are formed when metals combine with non-metals. Forming ions Metal atoms lose electrons to form +ve ions. Non-metal
NAME 1. When compared to H 2 S, H 2 O has a higher 8. Given the Lewis electron-dot diagram: boiling point because H 2 O contains stronger metallic bonds covalent bonds ionic bonds hydrogen bonds 2. Which
Most of the matter around you and inside of you is in the form of compounds. For example, your body is about 80 percent water. You learned in the last unit that water, H 2 O, is made up of hydrogen and
Chapter 2 Atoms, Molecules, and Ions 1. Methane and ethane are both made up of carbon and hydrogen. In methane, there are 12.0 g of carbon for every 4.00 g of hydrogen, a ration of 3:1 by mass. In ethane,
Chapter 2 The Chemical Context of Life Multiple-Choice Questions 1) About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living
Atoms and the Periodic Table The very hot early universe was a plasma with cationic nuclei separated from negatively charged electrons. Plasmas exist today where the energy of the particles is very high,
Why? The chemical properties of an element are based on the number of electrons in the outer shell of its atoms. We use Lewis dot structures to map these valence electrons in order to identify stable electron
Atoms and Molecules Preparation Grade Level: 5-8 Group Size: 20-30 Time: 60 90 Minutes Presenters: 2-4 Objectives This lesson will enable students to: Describe how atoms are the building blocks of matter
3 CHEMICAL FOUNDATIONS: ELEMENTS, ATOMS AND IONS All matter is built up from chemical combinations of elements. As of 2003, there are 114 known elements, of which 88 are naturally occurring; the remaining
Name: Date: Student Exploration: Electron Configuration Vocabulary: atomic number, atomic radius, Aufbau principle, chemical family, diagonal rule, electron configuration, Hund s rule, orbital, Pauli exclusion
Answer the following questions. CHEMISTRY BONDING REVIEW 1. What are the three kinds of bonds which can form between atoms? The three types of Bonds are Covalent, Ionic and Metallic. Name Date Block 2.
Study Guide Chapter 5 Periodic Table Section 1: Arranging the Elements Pages 106-112 DISCOVERING A PATTERN 1. How did Mendeleev arrange the elements? a. by increasing density b. by increasing melting point
CHAPTER 9 THE PERIODIC TABLE AND SOME ATOMIC PROPERTIES PRACTICE EXAMPLES 1A 1B A B A Atomic size decreases from left to right across a period, and from bottom to top in a family. We expect the smallest
ANSWER KEY : PART I: ATOM SCREEN Build an Atom simulation ( http://phet.colorado.edu/en/simulation/build an atom ) 1. Explore the Build an Atom simulation with your group. As you explore, talk about what
Assignment 06 A 1- What is the energy in joules of an electron undergoing a transition from n = 3 to n = 5 in a Bohr hydrogen atom? a) -3.48 x 10-17 J b) 2.18 x 10-19 J c) 1.55 x 10-19 J d) -2.56 x 10-19
1 Introductory Chemistry, 3 rd Edition Nivaldo Tro Atoms and Elements Opening figure showing a shore scene with molecules of O 2, N 2, triethyl amine (CH 3 CH 2 ) 3 N, and rocks made of silicates containing
2.13 Ionisation Energies Definition :First ionisation energy The first ionisation energy is the energy required when one mole of gaseous atoms forms one mole of gaseous ions with a single positive charge
CHAPTER EIGHT BNDING: GENERAL CNCEPT or Review 1. Electronegativity is the ability of an atom in a molecule to attract electrons to itself. Electronegativity is a bonding term. Electron affinity is the
Sample Exercise 2.1 Illustrating the Size of an Atom The diameter of a US penny is 19 mm. The diameter of a silver atom, by comparison, is only 2.88 Å. How many silver atoms could be arranged side by side