Chapter 7 - Atomic Structure and Periodicity - Active Learning Questions - Page 341: 17

2p orbital is higher in energy, and this is also true for helium.

2p orbital is higher in energy, and this is also true for helium. If the 2s orbital were higher in energy, elements like Li would put their 3rd electron in the 2p orbital, but they don't so 2p must be higher energy.