Question

how many valence electrons are in al⁺?

Explanation:

Step1: Determine Al's electron - configuration

Al (aluminum) has an atomic number of 13. Its ground - state electron configuration is $1s^{2}2s^{2}2p^{6}3s^{2}3p^{1}$.

Step2: Analyze $Al^{+}$ formation

When Al forms $Al^{+}$, it loses one electron. The electron is lost from the highest - energy orbital, which is the 3p orbital. So the electron configuration of $Al^{+}$ is $1s^{2}2s^{2}2p^{6}3s^{2}$.

Step3: Identify valence electrons

Valence electrons are the electrons in the outermost shell. For $Al^{+}$, the outermost shell is the third shell ($n = 3$), and there are 2 electrons in the 3s orbital.

Answer:

2