Which statement describes the general trends in electronegativity and atomic radius as the elements in period 2 are considered in order from left to right?

(1) both electronegativity and atomic radius increase.
(2) both electronegativity and atomic radius decrease.
(3) electronegativity increases and atomic radius decreases.
(4) electronegativity decreases and atomic radius increases.

#3 would be the correct answer.
explanation:
1) electronegativity, the attractive force of an atom to a pairing electron, would increase due to the octet rule (each atom tries to obtain a full valance shell)
2) atomic radius increases because the more electrons there are in the valance shell, the more attractive protons forces are required to hold them in their place. However, elements cannot loose or gain protons. Therefore, there are less attractive forces, which causes the electrons to be farther away from the protons, and thus there is a larger atomic radius.

The answers is a nuclear changes