Question

The first ionisation energy $\left(I{E}_1\right)$ of 5d elements are higher than those of the 3d and 4d elements.

If it is true enter 1, else enter 0.

Answer 1

The first ionisation energy of 5d elements are higher than those of the 3d and 4d elements. This is due to greater effective nuclear charge acting on outer valence electrons because of the weak shielding of the nucleus by 4f-electrons.

Hence, the correct answer is 1.