Answer:
Neon (Ne)
Explanation:
The atomic number of Chlorine is seventeen and its number of valance electrons are seven, so number of core electrons will be ten.
Valance electrons;
These are the electrons which are present in put most valance shells and take part in bonding.
Core electrons:
These are the electrons present in inner to the valance shell and closer to the nucleus. These electrons do not take part in bonding.
Electronic configuration:
Cl₁₇ = 1s² 2s² 2p⁶ 3s² 3p⁵
Core electrons = 1s² 2s² 2p⁶ = 10
Valance electrons = 3s² 3p⁵ = 7
The number of core electrons are ten and atomic number of neon is also ten. So, the number of core electrons of chlorine will be equal to the total number of electrons of neon.
