I need answers to a and b, please

Thank you

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. : )

The reaction q+r2=r2q is found to be first order in r2 and

This is a characteristic of the elements in the periodic table that shows a pattern. it may increase or decrease across or down the table.