Question

An electron in a helium atom transitions from a 2p orbital to a 1s orbital. The difference in energy between the two states is 3.40 x 10^-18 J. Which of the following best describes how the energy of the helium atom is affected by the electronic transition?

A) The energy of the helium atom decreases.
B) The energy of the helium atom increases.
C) The energy of the helium atom remains the same.
D) The energy change cannot be determined from the given information.

Answer 1

The energy of the helium atom decreases when an electron transitions from a 2p orbital to a 1s orbital, as it emits energy in the form of a photon.

Step-by-step explanation:

When an electron in a helium atom transitions from a 2p orbital to a 1s orbital, the energy of the helium atom decreases. This is because the transition of an electron to a lower energy level releases energy, in this case, 3.40 x 10^-18 J, in the form of a photon. The energy levels of orbitals can be generally represented as 1s < 2s < 2p < 3s < 3p < 4s, with 1s being the lowest energy level. Since the electron moves from a higher to a lower energy level (from 2p to 1s), it is moving to a more stable and lower energy state, and the atom subsequently loses energy.