Question

Assertion: All the isotopes of a given element show same chemical behaviour.
Reason: Isotopes have different number of neutrons present in the nucleus.

• A. If both assertion and reason are true and reason is the correct explanation of assertion.
• B. If both assertion and reason are true but reason is not the correct explanation of assertion.
• C. If assertion is true but reason is false.
• D. If both assertion and reason are false.

Answer 1

Answer: (B)

Isotopes are defined as the atoms with same atomic number (protons or electrons) but different mass number (or neutrons). Mass number determines the physical properties such as boiling/melting/density etc. But chemical properties are governed by atomic number (number of electrons) and thus isotopes have similar chemical properties.