Atomic number of an element is 17 and mass number is 35. How many protons and neutrons are in the nucleus of an atom of this element?
Problem solving strategy:
Number of protons are equal to atomic number and number of neutrons $=$ mass number $-$ atomic number
Number of protons $=$ atomic number $=$ 17
Number of neutrons $=$ mass number $-$ atomic number
$= 35 - 17 = 18$