Honors Chemistry Unit 4 ( )

Transcription

1 Honors Chemistry Unit 4 ( ) Families (research and present) Metals/nonmetals Trends o Atomic radius o Electronegativity o Ionization energy o Metallic and nonmetallic character Review Ions Oxidation # s 1

2 We are learning to: 1. Describe the history/arrangement of the periodic table. 2. Describe periodicity as a result of electron configurations. 3. Give the name and formula with charge for the polyatomic ions. We are looking for: 1a. Doberiener arranged the elements into triads. 1b. Newlands arranged the elements by the law of octaves. 1c. Mendeleev arranged the elements by atomic mass (periodic law). 1d. Moseley arranged the elements by atomic number (modern periodic law). 1e. Identify and describe the unique properties of the families on the periodic table (alkali metals, alkaline earth metals, transition metals, inner transition metals, post transition/other metals, metalloids, halogens, noble gases, other nonmetals, hydrogen). 2a. Identify the number of valence electrons using the periodic table or given an electron configuration. 2b. Describe the periodic trends (metallic character, electronegativity, ionization energy, atomic radius, ionic radius). 3a. Given the name of a polyatomic ion, write the corresponding formula and charge. 3b. Given the formula and charge of a polyatomic ion, write the corresponding name. ~ B.C.: Periodic Table History elements:,,, By, elements were known. ~ : Wrote the first extensive list of elements. : (German Chemist) Noticed that,, and had similar properties and that Br s atomic mass was between that of Cl & I. He found three other groups with similarities and he called these groups. 2

3 : (English Chemist) Arranged the now known 62 elements from to. He noticed that every element had chemical and physical properties; their properties were repeating. This became known as o Li Be B C N O F o Na Mg Al Si P S Cl : (Russian Chemist) Organized the elements by atomic also but also made it into form to help his students. Elements with properties were put into the same. Original Periodic Law : the properties of the elements are a function of their atomic masses. Considered the of the modern periodic table. He left where elements seemed to be. There were places where elements were put before elements because of their : o Te-I Co-Ni - (He felt the mistake was in measuring the mass and this would be corrected with further research.) : (English Chemist) Arranged elements by atomic. Gave rise to the new Periodic Law, Properties of the elements are a periodic function of their : Glenn Discovered new elements. Only living person for whom an element was named. elements have been identified (naturally and artificially). o elements occur naturally on Earth. Examples: gold, aluminum, lead, oxygen, carbon o elements have been created by scientists. Examples: technetium, americium, seaborgium 3

4 Periodic Table Terminology /Series = /Family = Metals Located to the of the staircase line. Characteristics: o to form positive (+) ions (cations) o o o o o React with Most metallic element (most reactive metal) = Nonmetals Located to the of the staircase line. Characteristics: o Tend to to form negative (-) ions (anions) o o o Most nonmetallic element (most reactive nonmetal) = Metalloids (Semimetals) Located and of the staircase line, except,, and. Characteristics: o o o o 4

5 Element Directions: ( is our assigned element) Due Date: You need an unopened following: On one side:. Decorate it with the -assigned element symbol -element name - atomic # (above the symbol) -average atomic mass (below the symbol) Another side: -who discovered & when -where did the element name come from? -picture of the element. -at least 3 uses for the element & pictures of uses. Another side: -3 physical properties -3 chemical properties -orbital notation -electron configuration -Nuclear symbol for the most common isotope of the element If you can t fit all the information for a side on that side, it can be placed on the another side. You will be presenting your creation to the class on the due date. 5

6 Families on the Periodic Table 6

7 Family Name Hydrogen List Elements (Solid/Liquid/Gas) (Metal/Metalloid/Nonmetal) Characteristics Alkali Metals Alkaline Earth Metals Transition Metals Other Metals (Post transition) Metalloids 7

8 Family Name Other Non metals List Elements (Solid/Liquid/Gas) (Metal/Metalloid/Nonmetal) Characteristics Halogens Noble Gases Lanthanoids (Inner transition metals) Actinoids (Inner transition metals) New Elements 8

9 Oxidation Numbers: The charge an atom acquires by gaining or losing electrons. Label your periodic table with oxidation numbers as instructed by your teacher. Isoelectronic Configurations Elements with similar electronic configurations tend to have similar chemical and physical properties. It is possible for elemental ions to have exactly the same electronic configuration as other elements or ions. When two elements and/or ions have the same electronic configuration it is said that they are "isoelectronic" with one another. When two chemical species are isolectronic they again tend to have similar chemical properties. Examples of Isoelectronic Elements and/or Ions Element or ion pair Electronic configuration Li +, He 1s 2 Be 2+, He 1s 2 F -, Ne 1s 2 2s 2 2p 6 S 2-, Ar 1s 2 2s 2 2s 6 3s 2 3p 6 Mg 2+, Na + 1s 2 2s 2 2p 6 Ca +, K [Ne]4s 1 P 3-, S 2-1s 2 2s 2 2p 6 3s 2 3p 6 Which of the atoms/ions are isoelectronic with each other? C, Cl -, Mn 2+, B -, Ar, Zn, Fe 3+, Ge 2+ 9

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11 Properties of Metals, Nonmetals, & Metalloids Define the following terms/physical properties & determine how you can test a sample for this property. 1) Malleability 2) Luster 3) Conductivity 4) For reactivity with acid, how will you determine if a chemical reaction has occurred? Purpose: To classify unknown samples as metal, nonmetal, or metalloid based on the observed characteristics. Use the procedures you described above to test each physical property of the samples. To test the chemical property (reaction w/ acid) place a small piece of the sample into a test tube and then add 5-10 drops of acid. Record your observations in the table on the back. 11

12 Properties of Metals, Nonmetals, & Metalloids Table Sample # Color Luster (lustrous) Malleability (malleable) Conductivity Reaction w/ acid Classification See your notes for the basic properties of metals, nonmetals, and metalloids. Then classify each of your samples as a metal, nonmetal, or metalloid. Metals Nonmetals Metalloids 12

13 Periodic Trends 13

14 "Periodic Table Properties (Trends) Atomic Radius Definition: Left to right across a period radius gets Why? 1. Electron electron Makes radius larger Very weak interactions 2. Proton electron Makes radius smaller Very strong interactions (proton to electron attraction is a million times stronger than electron to electron repulsion) Down a group/family radius gets Why? Energy level, n, from top to bottom Radius gets larger by adding electrons to higher (farther away) energy levels. Think Bohr model (adding rings) Ionization Energy The energy required to one electron from a neutral atom. Electronegativity The ability of an atom to electrons. Most electronegative element is F (fluorine). It is assigned the number 4. All other values are based on this value. Electron Affinity The energy change that occurs when a neutral atom an electron. 14

15 Ionic Radius: Na + Mg 2+ Al 3+ P 3- S 2- Cl - N 3- O 2- F - # of protons electronic structure of ion 2,8 2,8 2,8 2,8,8 2,8,8 2,8,8 2, 8 2, 8 2, 8 ionic radius (nm) (0.212) (0.171) Cations Anions The Anion radius is compared to the atom; Why? The Cation radius is compared to the atom; Why? When comparing ions of different elements, determine how many electrons each ion has and how many protons each ion has. If the electrons are the same, the one with more protons will have the smaller radius. Why? Which has a smaller atomic radius? K + or Cl - 15

16 Summary of Periodic Table Trends Top to Bottom Left to Right Atomic Radii Ionization Energy Electron Affinity Electronegativity Metallic Character 1. ionization energy (easy to remove electrons) 2. electronegativities (don t attract electrons) 3. Luster shiny 4. conductor of electricity and heat 5. and ductile Most metallic element = NonMetallic Character 1. ionization energy (hard to remove electrons) 2. electronegativities (attract electrons) 3. or no metallic luster 4. electrical and thermal conductors 5. solids Most nonmetallic element = Metalloid Character 1. Characteristics of both metals and nonmetals. 2. between those of metals and nonmetals. 3. energies between those of metals and nonmetals. 4. Boiling pts, Melting pts and vary widely. Example: Silicon high luster, brittle, good conductor 16

17 Periodicity Review Worksheet 1. Which atom in the following pairs would have the larger atomic radii? P or Cl P or Ge Mg or Ca Na or Mg K or Mg Sn or Pb Sn or As Al or Cl As or Se Cl or Br Si or S Sr or Ra Si or O Ca or Al H or He 2. Which ion in the following pairs would have the larger radii? Li + or Be 2+ Mg 2+ or Be 2+ Cs + or Be 2+ Cu + or Cu 2+ Cr 3+ or Cr 6+ Na + or Al 3+ Zn 2+ or Fe 2+ N 3- or F - S 2- or O 2- I - or Cl - P 3- or S 2- Br - or S 2-3. Which member of the following pairs would have a larger radii? Br or Br - S or S 6+ O or O 2- P or P 3- Ca or Ca 2+ Al or Al 3+ Li or Li + N 3- or Al Which atom in the following pairs would have the greater first ionization energy? Sr or Ba Cs or Ba Cl or Ar In or Sn Xe or Kr Mg or Sr Ca or Cu 5. What is the difference between electron affinity and ionization energy? 6. Which member in the following pairs would have the greater electron affinity & electronegativity? F or Cl F or O F or Any element S or Cl Ca or K Ca or F Al or Si S or O N or O Nonmetal or Metal C or S Mg or Na Na or K 7. What is the difference between a cation and an anion? 8. Identify three anions in Period 2 that can have the same number of electrons when they become ions. Do they gain or lose electrons? 9. Identify three cations in Period 3 that can have the same number of electrons when they become ions. Do they gain or lose electrons? 10. Identify the ions that are most likely to have an ion charge (oxidation state) of -2? (Hint: there are five of them) 17

18 11. Identify the ions that are most likely to have an ion charge (oxidation state) of +2? (Hint: there are six of them) 12. Why do elements in the same family generally have similar properties? 13. Which element has the greatest electron affinity? Why? 14. Which element has the lowest ionization energy? Why? 15. Consider all elements in period 3 for the following (Na through Ar) has the largest atomic radius has the greatest electron affinity has the highest first ionization energy is the most reactive metal is the most reactive non metal is the least reactive are metalloids are most likely to be cations are most likely to be anions loses 3 electrons to have noble gas configuration gains 3 electrons to have noble gas configuration 16. Consider all elements in group 16 (O through Po) is the least reactive is the most reactive has the greatest electron affinity has the greatest first ionization energy has the smallest atomic radius 17. In a given period, are cations larger or are anions bigger? 18. Is the radius of a cation larger or smaller than the neutral atom? Why? 19. Is the radius of an anion larger or smaller than the neutral atom? Why? 18

19 Name Honors Chemistry Practice Quiz The Periodic Law : "Trends" Answer the following problems by placing the correct letter next to the problem number. For problems 1-5 indicate with answer "a" the element you would predict with the highest ionization energy. Continue ranking the elements down to the lowest. a. highest b. second highest c. third highest d. second lowest e. lowest Rubidium Cesium Tin Yttrium Francium For problems 6-10 indicate with answer "a" the element you would predict with the largest atomic radius. Continue ranking the elements down to the smallest. a. largest b. second largest c. third largest d. second smallest e. smallest Tantalum Magnesium Mercury Polonium Sulfur For problems indicate with answer "a" the element you would predict with the highest electronegativity. Continue ranking the elements down to the lowest. a. highest b. second highest c. third highest d. second lowest e. lowest Cesium Fluorine Oxygen Francium Nitrogen For problems indicate with answer "a" the element you would predict with the highest reactivity. Continue ranking the elements down to the lowest. a. highest b. second highest c. third highest d. second lowest e. lowest Rubidium Cesium Tin Yttrium Francium For problems indicate with answer "a" the element you would predict with the metallic characteristics. Continue ranking the elements down to the lowest. a. highest b. second highest c. third highest d. second lowest e. lowest Sodium Argon Thallium Calcium Zinc 19

20 Name Class Period Ion Practice 1. An isotope has 106 proton, 157 neutrons, and 106 electrons: a. Write the nuclear symbol for this isotope b. What is the name of this element? c. Is this an atom or an ion? d. What is the mass number of this isotope e. What is the atomic number? f. What is the net charge? 2. An isotope has 29 protons, 34 neutrons, and 28 electrons: a. Write the hyphen notation for this isotope b. What is the name of this element? c. Is this an atom or an ion? d. What is the mass number of this isotope e. What is the atomic number? f. What is the net charge? 3. a. The species 104 Rh 3+ has protons, neutrons and electrons b. The species 12 C has protons, neutrons and electrons c. The species 130 Te -2 has protons, neutrons and electrons 4. Which element will produce an ion with 15 protons, 16 neutrons and 18 electrons?. 5. Which element will produce an ion with 20 protons, 20 neutrons and 18 electrons?. 20

21 6. a. A Calcium atom will (lose or gain) electrons. How many? Is the calcium atom bigger or smaller than the calcium ion? b. A Francium atom will (lose or gain) electrons. How many? Is the francium atom bigger or smaller than the francium ion? c. A Fluorine atom will (lose or gain) electrons. How many? Is the fluorine atom bigger or smaller than the fluorine ion? d. A Oxygen atom will (lose or gain) electrons. How many? Is the oxygen atom bigger or smaller than the oxygen ion? e. A Carbon atom will (lose or gain) electrons. How many? Is the carbon atom bigger or smaller than the carbon ion? 7. Considering a 26 Mg atom and and a 26 Mg 2+ ion, label the following true or false: They both have the same number of protons They both have the same number of electrons They both have the same number of neutrons The magnesium ion has 14 electrons and the magnesium atom as 10 electrons The net charge on the magnesium ion is 2+ The Bohr model of the magnesium ion has 0 electrons in the outer most shell. The Mg 2+ ion is larger than the Mg atom. 21

22 Martian PT Name Honors Chemistry Worksheet "Trends" "Periodic Chart For Mars And Its 33 Known Elements" Place the following elements in their proper place in the Martian periodic table. Remember, natural laws are the same for the whole universe. Note that Mars has no transition metals. a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z,!, #, $, %, +, =,? undiscovered 1. The most reactive metallic element is x. 2. The most reactive nonmetallic element is!. 3. Inert gases (like our noble gases) are $, %, a, and d. a has the highest ionization energy of this group and the least dense, $ has the lowest ionization energy for this group, and d has a smaller atomic radius than %.. 4. The lightest element of all is #. 5. All the following elements are in the 3rd energy level and have n is the largest atomic radius g is a metalloid = is the most reactive nonmetal? is a pretty reactive metal + is next to k but k has the higher ionization energy e is in this period as well 6. Element g has 14 protons. 7. f has a total of 7electrons. 8. c has an atomic mass of 5 and its final electron is in the 2 nd energy level. 9. r would correspond to our alkali metals and is in the 4th energy level. 10. The! family is made up of the elements!, =, s and p in order of increasing atomic radii. 11. j is the most dense of all Martian atoms and is radioactive and its electron configuration would end with 5p

23 12. q is in period 5 and has an oxidation number of m is in period 2 and will form a compound with! that has the formula m! 2. In other words, m has two electrons that it would like to give to!. 14. h is like our element carbon and is in same family as t, w and g. 15. t is bigger than w in atomic radius. 16. The Martian solvent is like our most important liquid and has the formula # 2y. 17. o is in the same family as e and has a lower electronegativity than e. 18. i is the only metalloid in the family of y. 19. l has a dot notation of 3 dots and an oxidation number of z is in the same family as q and has a slightly higher ionization energy than q. 21. b is slightly smaller that q. 22. u has a final electron configuration of 4p v is next to s and has a larger atomic radius than s.. Extension Problems: A. If you discovered the Martian element that is listed as undiscovered at this time on the Martian periodic table, what would you name it? B. What chemical symbol would you give this element and why? C. Name at least three characteristics that this element would have because of its location on the Martian periodic table? 23

24 Periodic Table Trends Review Worksheet For each of the following, circle the correct element 1. Li Si S Metal 2. N P As Smallest Ionization Energy 3. K Ca Sc Largest Atomic Mass 4. S Cl Ar Member of the Halogen Family 5. Al Si P Greatest Metallic Characteristics 6. Ga Al B Largest Atomic Radius 7. V Nb Ta Largest Atomic Number 8. Te I Xe Member of Noble Gases 9. Si Ge Sn Has electrons in 4 energy levels 10. Li Be B Member of Alkali Metals 11. As Se Br Largest Electronegativity 12. H Li Na Nonmetal 13. Hg Tl Pb Member of Transition Metals 14. Na Mg Al Electron distribution ending in s 2 p Sb Bi Pb Metalloid 16. B C N Greatest Nonmetal characteristics 17. Ca Sc Ti Electron distribution ending in s 2 d Be K Ga Member of the Alkaline Earth Metals 19. Si Al P Semiconductor 20. F - Cl - I - Smallest Radius 24

25 Honors Chemistry Review Unit 4 1. What contribution did the following people make to the creation of the periodic table: a. Newlands: b. Mendeleev: c. Moseley: d. Dobereiner: 2. What does the new periodic law state? 3. In the periodic table, the vertical columns are called and the horizontal rows are called. 4. Elements in the same group have the same number of. 5. What family of the periodic table is the most stable because their valence shell is full of electrons? 6. Give three properties of metals: 7. Give three properties of nonmetals: 8. What is ionization energy? 9. Why does the ionization energy decrease as you move down a group? 10. Why does the atomic radius increase as you move down a group? 11. As you move across a period, the decreases and the,, and increases. 12. As you move down a group, the atomic radius and the ionization energy, electron affinity, and electronegativity. 25

26 For questions #13-36, use the following elements to answer the questions. Elements may be used more than once and for some questions, there will be more than one answer. Na Si Br Ag Ne Sb H Ga S Ca Es Pa Cl Ba Li He Xe Fr F Al 13. The most reactive metal: 14. The most reactive nonmetal: 15. A metal: 16. A nonmetal: 17. A metalloid: 18. A halogen: 19. An alkali metal: 20. An alkaline earth metal: 21. A noble gas: 22. A transition metal: 23. A post transition metal: 24. An inner transition metal: 25. Other nonmetal: 26. In a family all by itself: 27. Radioactive: 28. Made in a laboratory: 29. A gas: 30. Found in a free-state (not part of a compound): 31. Has multiple oxidation states: 32. The only noble gas that does not contain eight valence electrons: 33. Has the same number of valence electrons as Nitrogen: 34. Has the same oxidation state as Potassium: 35. Has an oxidation state of -1: 36. Has 4 valence electrons: 26

27 Trends in the Periodic Table 1. On the top graph, plot ionization energy (y-axis) vs, atomic number (x-axis). On the bottom graph, plot a separate graph of atomic radius (y-axis) vs, atomic number (x-axis). For each graph, connect successive dots with straight lines, label the axes, and include a title. 2. In order to make the graph easier to analyze, you should mark each group of elements with the same color circle/dot. a. Group 1 Alkali Metals = Red (H, Li, Na, K) b. Group 2 Alkaline Earth Metals = Blue (Be, Mg, Ca) c. Group 3 Boron Family = Green (B, Al) d. Group 5 Nitrogen Family = Orange (N, P) e. Group 7 Halogens = Yellow (F, Cl) f. Group 8 Noble Gases = Purple (He, Ne, Ar) 3. Examine your graph of atomic radius vs. atomic number. a. Which elements are found at the main peaks on your graph? i. What do these elements have in common? b. Which elements are found at the main valleys on your graph? i. What do these elements have in common? 4. Generally, as you go from left to right across a period, what happens to atomic radius? Explain why. 5. Generally, as you go down a group in the periodic table, what happens to atomic radius? Explain why. 6. Examine your graph of ionization energy (IE) vs. atomic number. a. Which elements are found at the main peaks on your graph? i. What do these elements have in common? b. Which elements are found at the main valleys on your graph? i. What do these elements have in common? 27

28 7. Generally, as you go from left to right across a period, what happens to IE? Explain why. 8. Generally, as you go down a group in the periodic table, what happens to IE? Explain why. 9. Why do you think there is an inverse relationship between atomic radius and ionization energy? 28

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