Chlorine has an atomic number of 17.

How many protons are in an atom of chlorine?

A. 17

B. 18

C. 35

D. 52

A. 17

Answer: The correct answer is Option A.

Explanation:

Atomic number is defined as the number of protons or number of electrons that are present in a neutral atom. It is represented by the symbol 'Z'

Z = Atomic number = number of protons = number of electrons

We are given:

Atomic number of chlorine = 17

So, number of protons = 17

Hence, the correct answer is Option A.