Question

how many valence electrons does this atom have?
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p³
2
10
3
5

Explanation:

Step1: Identify the valence shell

The valence shell is the outermost shell. For the electron configuration \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{3}\), the outermost shell is the 4th shell.

Step2: Sum the electrons in the valence shell

The electrons in the 4th shell are \(4s^{2}\) and \(4p^{3}\). The number of electrons is \(2 + 3=5\).

Answer:

5