When is thermal energy trapped in the dense center of a cloud?
A)when the gravity becomes so strong that photons cannot escape
B)when excited molecules collide with other molecules before they can release a photon
C)when the cloud becomes so hot and dense that nuclear fusion begins
D)when magnetic fields trap the radiation
E)when the cloud cools down so much that less light escapes than is produced by contraction

Question

Quizplus · Accepted Answer

Thermal energy is trapped in the dense center of a cloud when excited molecules collide with other molecules before they can release a photon, leading to a build-up of thermal energy. This is known as collisional trapping.

When Is Thermal Energy Trapped in the Dense Center of a Cloud