4. Chlorine-35 atom and Chlorine-37 atom are called isotopes...Use these two examples to explain what is 'isotopes'
Isotopes are different atoms of the same element which have the same number of protons but different number of neutrons.
Chlorine-35 have 17 protons and 18 neutrons whereas chlorine-37 have 17 protons too but have 20 neutrons since Chlorine-37 have a different number of neutrons than Chlorine-35 they are isotopes.