Bonding+Practice+Test+_2+Key

Practice Test 2 Answer Key 1. covalent bond 2. ions 3. chemical bond 4. valence electron 5. molecule 6. metallic bond 7. B 8. C 9. A 10. C 11. B 12. Answers will vary. Sample answer: The oxygen atom gains two electrons in its second energy level to have 8. 13. brittleness, high melting point, high boiling point 14. Write the symbol of the element and place one dot around the symbol for each valence electron. 15. Answers will vary. Sample answer: Diatomic molecules are molecules made of two atoms of the same element; one example is oxygen. 16. Answers will vary. Sample answer: Metallic bonds due to moving electrons allow metal to be shaped. 17. Answers will vary. Sample answer: The way an element bonds is determined by the number of valence electrons. The number of valence electrons can be determined by the group number of the element in the periodic table. 18. The first level is closest to the nucleus and can hold 2 electrons. The second level can hold up to 8, only after the first level is full. The third level also hold up to 8 once the first two levels are full. 19. Carbon has 4 valence electrons and neon has 8 valence electrons. Neon would be less likely to form bonds than carbon because it already has a full outer energy level. 20. The chlorine atom began with 17 positively charged protons and 17 negatively charged electrons. It then gained one electron and became a chloride ion with a charge of 1–. 21. The carbon atom has 4 valence electrons and needs 4 more to have a filled outer energy level. 22. The sulfur atom has 6 valence electrons. It can share 2 electrons with another atom or gain 2 electrons from another atom to get a filled outer energy level.