Question

30. Which is true of atoms X and Y if they are isotopes of the same element?

A. X and Y have the same atomic number and mass number.
B. X and Y have the same number of protons but different number of neutrons
C. X and Y have the same mass number but different atomic number.
D. X and Y have the same number of neutrons but different number of protons

Answer 1

Answer: B

Explanation: ISOTOPE has the same atomic number but a different mass number. Isotopes have same chemical properties ( same number of electrons) but different physical properties(as they have different masses).