Question

1.) If a neutral atom of chlorine has 17 electrons and 18 neutrons, how many electrons are in the second energy shell of this atom?

2.) If a neutral atom of chlorine has 17 electrons and 18 neutrons, how many electrons are in the outermost, or valence, shell of this atom?

Answer 1

Answer: 1. 8 electrons

2. 7 electrons

Explanation: energy shell are orbits which Carry's electrons around an atom's nucleus.

To determine the number of electrons in an energy shell, use the formula

2(n^2)

n= number of energy shell

Therefore the second energy shell is n=2

Substituting n in the equation above,

2(2^2)=8

2. Valence electrons are the electrons on the outermost shell of an atomic nucleus.

The group number of an element is the same as the valence electrons of that element.

Therefore chlorine which belongs to group 7 elements has 7 valence electron.

We can also get the valence electrons using the K L M N shell.

The K shell which has maximum of 2 electrons, while other shells can contain maximum of 8 electron.

SEE PICTURE ATTACHED TO UNDERSTAND THE K L M N SHELL BETTER.