Quiz 2 1 An atom with the chemical symbol 35 17 X has protons and electrons. 2 Two atoms with the same number of protons and a different number of neutrons are called. 3 The nucleus of an atom contains,,. 4 The isotope 151 63 Eu has protons and neutrons. 5 Elements to the left of the periodic table are classified as. 6 Referring to the periodic table list three ionic and covalent compounds 7 is the ability of an atom in a molecule to attract the shared electrons in a bond. True or false 8 Elements differ from one another according to the number of electrons. 9 In the chemical reaction, the atoms are rearranged but are not broken apart or destroyed. 10 An excited atom can return to the ground state by emitting electromagnetic radiation. 11 An electron in the n=3 state can go to the n=1 state by absorbing energy. 12 The lowest numbered principal shell in which f orbitals are found is 1. 13 The sublevel p has three orbitals and can accommodate up to six electrons. 14 The longer the bond length in a covalent bond, the stronger the bond. Electron configurations 15 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 7 is electron configuration of.
16 Phosphorous has electrons in its outermost principal level. 17 The maximum number of electrons allowed in the fourth energy level is. 18 Arrange the following elements in increasing atomic size and ionization energies: S, F,, P, B. 19 Loss electron(s) leads to charged ion. 20 Write electron configuration and Lewis structure of As and its possible ion. Valence electrons, Lewis structures, bonding and lone pairs, bond polarity, resonance structures and molecular shapes or geometries using VSEPR for the following: 1 N 3-2 S 3 3 CCl 3 4 2 Se
CE-100 Quiz 2 Spring 2009 V. Joshi 1. Arrange the following elements in order of increasing atomic radius Na, Al, P, Cl 2. Arrange the following elements in the order of increasing ionization energy: Sb, Te, Sn, Sr 3. An ion contains 78 electrons and 126 neutrons. If the charge of the ion is 2+, find out what is its parent element and its mass number. 4. alogens are very reactive group because: (a) They need to gain only one electron to satisfy the octet rule (b) They have 7 electrons in the valence shell, and the more electron an atom has the more reactive it is. (c) They are nonmetals, and all nonmetals are reactive. (d) They can easily lose their seven electrons to satisfy the octet rule. 5. Write the ground state electron configuration for the following. Indicate whether the octet rule is satisfied or not. ctet rule satisfied? (Y/N) (a) Ar (b) Na 1+ (c) C 2- (d) 2- (e) Ca 2+ 6. What are the group number, period number and name of the element whose electron configuration is 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 2? Group number Element name Period number 7. Regarding the nth period element whose position is indicated with an x, which statement is (are) true? a) The element is a representative nonmetal b) The element is a transition metal c) The element is in the p block d) The element is in the d block e) The valence electron configuration is ns 2 (n-1)d 3
CE-100 Quiz 2 Spring 2009 V. Joshi f) The valence electron configuration is nd 5 g) The valence electron configuration is (n-1)d 4. 8. What is wrong with the following dot diagram for C?..... C Ȯ..... a) There are too many electrons b) The octet rule is not satisfied c) There is a double bond between C and d) All of the above 9. Draw Lewis structure of C or the carbon monoxide. 10. Consider the hypothetical species dilithium, Li 2, made of two metallic Li atoms. Predict what kind of bonding such a species would have a) Ionic b) Covalent c) Polar covalent 11. Classify the bonds in each of the following as ionic, covalent, or polar covalent, given the following electronegativity of the elements: a) Br 2 (Br: 2.8) b) PCl 3 (P: 2.1, Cl: 3.0) c) LiCl (Li: 1.0, Cl: 3.0) d) ClF (Cl: 3.0, F: 4.0) e) MgCl 2 (Mg: 1.2, Cl: 3.0) 12. Complete the following table: Ion # valence Lewis Molecular Dipole. Mol. electrons structure Geometry or non-polar S 3 2- C 3 Cl N 2 C 2 4
Quiz 2 answers: CE 100 Spring 2009 1. Cl, P, Al, Na 2. Sr, Sn, Sb, Te 3. 206 80 g 2+ 4. a 5. a) 1s 2, 2s 2, 2p 6, 3s 2, 3p 6 ; Y b) 1s 2, 2s 2, 2p 6, 3s 0 ; Y c) 1s 2, 2s 2, 2p 4 ; N d) 1s 2, 2s 2, 2p 6 ; Y d) 1s 2, 2s 2, 2p 6, 3s 2, 3p 6, 4S 0 ; Y 6. IV, 4, Ge 7. e 8. a 9. :C : 10. Covalent 11. a) Covalent; b) Polar Covalent; c) Ionic; d) Polar Covalent; e) Ionic 12. 26; Trigonal pyramidal; 107º; Dipole 3- S or S 14; Tetrahedral; 109.5º; Dipole C Cl 10; N=N; No Central Atom; Non polar 12; trigonal planar; Non polar C C
Quiz 2 CE 100 1. 17, 17 2. Isotopes 3. Protons, neutron, 4. 63, 88 5. Electro-positive or alkali and alkaline earth 6. NaCl, K 2, MgBr 2 (ionic between electro-positive and electronegative elements); S 3, C 4, N 3 (between non metals). 7. Electronegativity 8. F 9. T 10. T 11. F 12. F (it is 4; 4s, 4p, 4d and 4f) 13. T 14. F 15. Cobalt 16. 5 17. 32 18. Increasing atomic size: F,, B, S, P; increasing ionization potential: P, S, B,, F 19. positively charged ion or cation 20. As and As 3-21. Bonding and VESPER
1-22. N Trigonal planar, 120º, non-polar; two additional resonance structures. 23. S Trigonal planar, 120º, non-polar additional; two additional resonance structures. 24. CCl 3 is also in the previous quiz 25. Se Bent, 119º, polar, one additional resonance structure