In the ground state, an atom of which element has seven valence electrons?
1.
sodium
2.
phosphorus
3.
nitrogen
4.
fluorine

Fluorine

Explanation:

Fluorine has 9 total electrons. The first two are in the 1s level, and the remaining electrons are on the outer level of the atom, with 2 in the s level and 5 in the p level. The electron configuration is 1s2 2s2 2p5.

answer; i believe the correct answer is (c) /// is a homogeneous mixture of gaseous substance nitrogen,oxygen and smaller amounts of other substancesmixtures can be either ( homogeneous or heterogeneous)plz check first good luck