It would be c. It can bond with other atoms through ionic and covenant bonds.<span />
The answer is a. the abiotic components of an ecosystem
It is D. alliteration
Alliteration is when it has the same letter or sound
I'm not exactly sure what specifically you are asking for in relationship to balancing equations, but I have some examples with working out so you can examine them and try to go through the steps with them.
Hope this helps! <3