Question

7. Which of the following pairs of atoms are isotopes? a) C14 & N14 b) U235 & U238 c) C12 & C12 d) C12 & N14 e) None of the choices are correct

Answer 1

b) U235 & U238

Step-by-step explanation:

Isotopes are the variants of a element which differ in the number of neutrons , and in the nucleon number consequently . All isotopes of the element have same number of the protons but different numbers of the neutrons.

(a) Isotopes are the properties of an element. Hence, not isotopes.

(b) Uranium is the element which exists in mass number 235 and 238 and they are the isotopes of the uranium element. Hence, they are isotopes.

(c) They represent same specie. Hence, not isotopes.

(d) Isotopes are the properties of an element. Hence, not isotopes.