Question

Neon and chlorine have atomic number 10 and 17 respectively. Their valencies will be __________ and __________________.

• A. zero
• B. -1

Answer 1

1. Neon

• Atomic number of Neon(Ne) = 10
• Electronic configuration = 2,8 its outermost shell is completely filled ,called octet. Hence, its valency is zero.

2. Chlorine

• Atomic number of Chlorine (Cl) = 17
• Electronic configuration = 2,8,7 its outermost shell can complete is by filled 1 electron. Hence, its valency is -1.

Therefore Neon and chlorine have atomic numbers 10 and 17 respectively. Their valencies will be zero and -1.