Question

What sublevel can you find the last electron for helium in?

Option 1: 1s
Option 2: 2s
Option 3: 2p
Option 4: 3s

Answer 1

The last electron for helium can be found in the 1s sublevel.

Step-by-step explanation:

The last electron for helium can be found in the 1s sublevel.

Helium atoms have 2 electrons. Both electrons fit into the 1s subshell because s subshells contain one s orbital which can hold up to 2 electrons; therefore, the electron configuration for helium atoms is 1s².