Question

write the electron configuration for an aluminum cation with a charge of +1.

Explanation:

Step1: Find neutral Al electron count

Aluminum (Al) has an atomic number of 13, so neutral Al has 13 electrons.

Step2: Adjust for +1 cation charge

A +1 charge means 1 electron is lost: $13 - 1 = 12$ electrons total.

Step3: Assign electrons to orbitals

Fill orbitals in order: 1s, 2s, 2p, 3s.

• 1s holds 2 electrons: $1s^2$
• 2s holds 2 electrons: $2s^2$
• 2p holds 6 electrons: $2p^6$
• 3s holds 2 remaining electrons: $3s^2$

Combine these orbitals in order.

Answer:

$1s^22s^22p^63s^2$