Achlorine atom has 7 valence electrons in its third shell. what will it do when forming an ion? a. gain 1 valence electron b. lose 1 valence electron c. gain 7 valence electrons d. lose 7 valence electrons

Its a, gain 1 valence electron

1. and 2. question: in which equation? or i don't understand you, 3. a), 4. c), 5. c), 6. b), 7. d), 8. d) if small number is underlined(behind symbol) , b) if big number is underlined(in front of symbol)9. what is underlined there? 10. c)