Can someone please correct these answers and tell me what I’m doing wrong?! Much appreciated!!!

1) how many electrons are in each energy level of the following elements? a. he b. na c. na d. ne 2) how many valence electrons are percent in the following atoms? a. s b. mg c. be d. cl 3) which of the following elements are stable as atoms? a. he b. o c. cl d. ar if you are able to provide the work as to how you got the answers that would be greatly appreciated. : )

What problem would a person have if the nucleic acid in one of his or her cells were damaged?

Iwll give extra points to who gets this for ! what type of reaction is this? ?