system
Given the following post, respond as if you're commenting on Reddit:
human
Why is an Alpha particle denoted as a Helium atom?

How is it that we aren't getting cancer after inhaling large volumes of helium gas to change our voice as kids?

What makes an alpha particle highly ionizing but not helium gas?
gpt
An alpha particle is a helium-4 nucleus resulting from the alpha decay of a radioactive nucleus. The typical amount of kinetic energy carried away by an alpha particle after an alpha decay is around 5 MeV. That's why alpha particles are ionizing radiation. 

Atoms in helium gas at STP have typical kinetic energies on the order of 0.025 eV, so they are not ionizing.