Eclipse is a shadow formed in space that makes the sun or moon invisible for some time. In solar eclipse umbra and penumbra is visible because.

This is what i found on google “according to the collision theory, the following criteria must be met in order for a chemical reaction to occur: molecules must collide with sufficient energy, known as the activation energy, so that chemical bonds can break. molecules must collide with the proper orientation.” i hope this information you.

Is there a picture to go along with this