Question

#1: Carbon has different isotopes. What is different between an atom of 12C and an atom of 13C?

A. number of protons in the nucleus

B. number of neutrons in the nucleus

C. number of electrons in the atom

D. number of protons and electrons in the atom

Answer 1

The atomic number of a neutral atom is equal to the number of protons and the number of electrons of the atom. The atomic weight meanwhile is equal to the sum of the number of protons and number of neutrons. Isotopes differ in the number of neutrons but the number of protons remain the same. In this case, the answer is B