Which of the following atoms has the highest first ionization energy?

Question

Which of the following atoms has the highest first ionization energy? (A) K (B) Sc (C) Rb (D) Na

Tardigrade Admin · Accepted Answer

Ionisation energy decreases with increase in the size of atom. Na,K,Rb belongs to alkali metal and down the group ionization energy decreases as size of atom increases down the group. Among the given elements, Sc being small has the highest ionization energy (.Na=496,K=419;Sc=631kJ(mol)- 1.)

Q. Which of the following atoms has the highest first ionization energy?

$K$

$S c$

$R b$

$N a$

Q. Which of the following atoms has the highest first ionization energy?

K

Sc

Rb

Na

Ionisation energy decreases with increase in the size of atom. Na,K,Rb belongs to alkali metal and down the group ionization energy decreases as size of atom increases down the group. Among the given elements, Sc being small has the highest ionization energy (Na=496,K=419;Sc=631kJ(mol)−1)

$K$

$S c$

$R b$

$N a$