Question

Which of the atomic number represents s -block elements?

• A. 7, 15
• B. 3, 12
• C. 6, 12
• D. 9, 17

Answer 1

Answer: (B)

3, 12

The elements in which the last electron enters the outermost s-orbital are called s-block elements.

The s-block elements have two groups ($1$ and $2$).

Thus, s-block elements include lithium $\left(Li\right)$ and magnesium $\left(Mg\right).$

The periodic table shows exactly where these elements are within the s-block.