A. what are isotopes?

b. how are the isotopes of a particular element alike?

c. how are they different?

Same number of element having same number of protons but different number of nutrons is called isotopes.

B; every elements has thier own isotopes like H has three isotopes protium, dutrium, tritium.

C; they are different from each othere due to having same number of protons but different number of nutrons.