An atom has 17 protons and 18 neutrons. Which symbol represents that atom, including its mass number?

35Cl

33Ar

32Cl

34S

35Cl

Explanation:

The number of protons in an element is it's atomic number. Atomic number of Cl is 17. So the element is chlorine. The total sum of the number of protons and neutrons gives the mass number. So mass number of Cl is 17+18=35. So the given atom is Chlorine with mass number

35.