Question

13 what letters represent the sub - levels?
a,b,c,d,f,g
s,p,d,f,g
s,d,p,f,q
12 what is the principle quantum number?
the energy level or period
the sub - levels
and unknown number
9 what element does not have 7 valence electrons?
mn
f
zn

Explanation:

Question 9

Valence electrons are outer - shell electrons. Fluorine (F) in group 17 has 7 valence electrons. Manganese (Mn) has 7 outer - shell electrons in its electron configuration. Zinc (Zn) in group 12 has 2 valence electrons.

The principal quantum number (n) represents the energy level or shell of an electron in an atom and is related to the period in the periodic table. Sub - levels are represented by the angular momentum quantum number (l).

The sub - levels in an atom are represented by the letters s, p, d, f, g.

Answer:

C. Zn

Question 12