How can helium escape the atmosphere?

Helium can escape the atmosphere due to its low Atomic Mass and high velocity at which its atoms move, allowing them to reach escape velocity. The Earth's gravitational pull is not strong enough to retain lighter gases like helium, especially at higher altitudes where the atmosphere is thinner. Additionally, solar radiation and other factors can contribute to the dispersal of helium into space. This process is gradual, leading to the eventual depletion of helium in the atmosphere over time.