Question

What is the valence electron in alkali metal?

• A. p electron
• B. d electron
• C. f electron
• D. s electron

Answer 1

Answer: (D)

s electron

Answer 2

Alkali metals belong to Group 1 of the periodic table. Their general outermost electronic configuration is $ns^1$, where 'n' represents the principal quantum number. This means that the valence electron (the electron in the outermost shell) is always an 's' electron. For example:

• Lithium (Li): $[He] 2s^1$
• Sodium (Na): $[Ne] 3s^1$
• Potassium (K): $[Ar] 4s^1$

In all these cases, the valence electron resides in an 's' orbital.