NCAE Chemistry: Which of the following statements about isotopes of hydrogen is correct?
a. They have the same number of protons.
b. They have the same number of neutrons.
c. They have different numbers of electrons.
d. they have different atomic number.
They have the same number of protons (and electrons for that matter) but different number of neutrons. So basically, they are elements with the same atomic number but different atomic mass. The number of neutrons is what's making the difference between the two.
