Which is larger O - or S 2- ? [ENDORSED]

[Nhi Vo 3A]

Which anion is larger O ^- or S ^ 2- ?

Give two reasons why.

[Tanner Baroni 3I]

S^2- is larger because atomic size increases as you go down the periodic table and it has a complete other orbital.

[Isaiah Little 1A 14B]

S2- is larger than O- because S2- has more protons and thus a stronger pull on its electrons than O- does, so it has a smaller atomic radius.

[Krupa Prajapati]

S^-2 is also larger because it has more electrons in its outer shell, which causes repulsion. This is called the shielding effect, and leads to S^-2 having a greater atomic radius than O^-