What element in period 3 has all 8 valence electrons

You encounter a solution that is acidic and you decide to test it by adding a small amount of a strong acid. the ph lowers slightly but is approximately unchanged, and still remains acidic. what can you say about the solution? a. it is a buffer solution. b. it is not a buffer solution it is a strong acid solution. d. the solution has been neutralized. e. the solution has excess acid present

How have the greenhouse gasses increased from the year 2000 to 2018

Elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?