Question

The elements inGroups$\mathbf{1}\mathbf{A}\left(1\right)$and$\mathbf{7}\mathbf{A}\mathbf{\left(}\mathbf{17}\mathbf{\right)}$are all quite reactive. What is the major difference between them?

Short answer

The major difference between them is given below:

The elements in Group $\mathbf{1}\mathbf{A}\left(1\right)$are metal while the elements in Group $\mathbf{7}\mathbf{A}\left(17\right)$are nonmetals.

The elements in Group $\mathbf{1}\mathbf{A}\left(1\right)$donate a single electron readily to form monovalent cations while the elements in Group 7A (17) accept a single electron easily to form monovalent anions.

Step-by-step solution

Elements in Groups 1A(1)

Alkali metals are metals present in Group $\mathbf{1}\mathbf{A}\left(1\right)$that lose one electron quickly to generate monocations.

Elements in Groups 7A(17)

The elements in Group $\mathbf{7}\mathbf{A}\left(17\right)$are nonmetals and have a special name called the halogens which gain one electron rapidly to generate monoanions.