Question

The electronic configuration of the element with Atomic number 19 is___________.

• A. 2,8,7
• B. 2,9,8
• C. 2,8,8,1
• D. 2,10,7

Answer 1

The correct option is C 2,8,8,1

The electronic configuration of the element with Atomic number 19 is 2,8,8,1 or $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^1$ or $\left[Ar\right]4s^1$. The element is potassium. It is an alkali metal with one valence electron.