Chapter 17, Problem 17STP

Interpretation Introduction

Interpretation:

The family of element having the lowest ionization energy in its period is to be identified.

Concept introduction:

The ionization energy is the amount of energy which is required to remove the electron form the outermost shell.

Answer to Problem 17STP

Correct answer: The alkali elements.

So, option C is correct.

Explanation of Solution

The ionization energy is minimum amount of energy which is required to remove the electrons from the outermost shell. It is represented in KJ/mol.

Alkali elements are the group 1^st element in periodic table which having the one electron in its outermost shell. So minimum amount of energy is required to remove this electron form outermost shell. So this element has lowest ionization energy.

Conclusion

Reasons for incorrect options:

For A: These have higher ionization energy as compare to alkali element.

For B : These also have high ionization energy.

For D: These elements have 2 valance electrons in its outermost cell.

For E: In outermost sell of halogens there are more electrons. So we require maximum amount of energy.