Ionization Energy in Metals.

Question 7: 
 a:Explain why metals have low ionization energy?

STATEMENT: Metals have low ionization energy.

REASONING:

As we know that the atomic size of metals usually increases when we move from top to bottom in a group. As valence electrons are far apart from the nucleus so the force of attraction is smaller and less energy is required to remove the electrons from their outer most shell. That is why metals have low ionization energy.

In a period from left to right, metals have low ionization energy and the metallic character decreases.

B: Explain why metals have high second ionization energy as compared to the first one?

STATEMENT:

“Removal of second electron from an atom requires more energy than the removal of the first one.”

REASONING:

When an atom has to lose more than one electron, the energy required to remove the electron at first attempt is called the first ionization energy.

Mg  àMg+ +e- (7.64 eV)

The energy required to remove the second electron is called second ionization energy. This energy is always greater than the first ionization energy because after the removal of the first electron the nuclear charge increases and the positive nucleus pulls the remaining electrons closer.

Mg+ à Mg++ +e- (15.03 eV)