Answer;
D. The group number is equal to the number of valence electrons.
Explanation;
-The valence electrons are the electrons in the outer shell of an atom. The valence electrons are the ones involved in forming bonds to adjacent atoms. Therefore, the number of valence electrons is important for determining the number of bonds an atom will form, the number of unpaired electrons, and an atom’s formal charge.
-For neutral atoms, the number of valence electrons is equal to the atom’s main group number.
Number of valence electrons = main group number (neutral atoms)
-The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.