1. a(n) forms when atoms share one or more pairs of electrons. a. metallic bond b. molecule c. covalent bond d. ionic bond 2. bonds are formed between a metal and a non-metals. a. metallic bond b. molecule c. covalent bond d. ionic bond 3. an element from group 2 and an element from group 16 are likely to form bond. a. metallic bond b. molecule c. covalent bond d. ionic bond 4. what is an exothermic reaction? a. a reaction where energy is absorbed b. a reaction where energy is released c. a reaction where energy is multiplied d. a reaction where energy is divided 5. what is the correct solution if you balanced the equation properly? a. 2 fe2o3 + 3c > 4fe + 3co2 b. fe2o3 + c > 4fe + 3co2 c. 2feo3 + 3c > fe + co2 d. 4feo3 + c > 3fe + 3co2 6. which statement about the law of conservation of mass is not true? a. the mass of reactants must equal the mass of products. b. all the atoms on the reactants side of an equation are also on the products side. c. the reaction creates new types of atoms. d. atoms are not lost, but are rearranged. 7. electrons involved in bonding between atoms are a. valence electrons b. inside the nucleus c. closest to the nucleus d. positively charged 8. the number of protons in the nucleus of an atom of that element is a. atomic number b. atomic weight c. mass number d. isotopes 9. when cars burn gas, it is an example of the carbon cycle. a. photosynthesis b. respiration c. combustion d. decomposition 10. one possible result of more carbon dioxide in the atmosphere is a. more nitrogen in the nitrogen cycle b. more carnivores in an area c. increase in rainfall in a region d. increase in average temperature on earth