Question

Which of the following statement (s) is/are incorrect for pair of elements Zr - Hf?

Options

• Both possess same number of valence electrons. 

• Both have identical sizes.

• Both have almost identical radii. 

• Both of these belong to same period of periodic table.

Answer 1

Both of these belong to same period of periodic table.

Explanation:

Zirconium (Zr) with atomic number 40 and Hafnium (Hf) with atomic number 72 belongs to period 5th and 6th respectively.