Question

Assertion : Alkali metals impart colour to the flame .

Reason : Their ionisation energies are low.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

Correct option (a) Both A and R are correct and R is the correct explanation of A.

Explanation:

Alkali  metals have very low value of ionisation energy as compared to other metals. So, valence electrons easily get excited and impart colour to flame.