Question 3 The element with electron configuration 1s^2 2s^s 2p^6 3s^2 3p^2
S (Z = 16).
Mg (Z = 12).
C (Z = 6).
Si (Z = 14).

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter  

idk what is it? is this a question that you know the answer or u dont