Question

Isotopes of an element have:
(This question has multiple correct options)
A) The same physical properties.
B) Same chemical properties.
C) Different number of neutrons.
D) Different atomic numbers.

Answer 1

Isomers refer to the organic molecules having the similar molecular formula but distinct arrangement of atoms in space. Isotopes on the other hand are the elements having the similar atomic number but distinct atomic mass.

Complete answer:
An isotope is actually one of two or more variants or forms of the same element. Now, let us discuss each statement or property about isotope in the given options:
Option A: Isotopes of the same chemical element possess distinct physical properties (such as boiling points, melting points, etc) because they possess different mass numbers (for e.g. carbon-12, carbon-13, carbon-14). Therefore, Option A i.e. The same physical properties are incorrect.
Option B: Chemical property of any element is due to the number of electrons and spatial arrangement of electrons. It does not depend on the neutrons. Isotopes of an element possess a similar number of electrons or protons but distinct numbers of neutrons. So all isotopes have the same chemical properties. Hence, Option B i.e. Same chemical properties are correct.
Option C: As already discussed, isotopes of an element possess different mass numbers (sum of protons and neutrons) which means that isotopes have different numbers of neutrons. Therefore, Option C i.e. Different number of neutrons is correct.
Option D: Isotopes refer to the atoms of an element having the normal number of protons as well as electrons but distinct numbers of neutrons. Thus, they have the same atomic number. Hence, Option D i.e. Different atomic numbers are incorrect.

Therefore the correct answers are Option B and Option C.

Note: Isotopes of an element possess the same chemical behaviour. However, the unstable isotopes can undergo spontaneous decay and they usually emit radiation and acquire a stable state. This feature of radioisotopes is very useful in food preservation, medical diagnosis and archaeological dating of artifacts.