Answer:
Hydrogen
1 valence electron
Helium
2 valence electrons
lithium
1 valence electrons
beryllium
boron
3 valence electrons
carbon
4 valence electrons
nitrogen
5 valence electrons
oxygen
6 valence electrons
flourine
7 valence electrons
neon
8 valence electrons
sodium
magnesium
aluminum
silicon
phosphorus
Answer: 17 Chlorine -1, +1, (+2), +3, (+4), +5, +7
18 Argon 0
19 Potassium +1
20 Calcium +2
Explanation:
