Atakes place when the sun, earth, and moon are in nearly a straight line with the earth being between the sun and the moon.
corona
lunar eclipse
solar eclipse

Lunar eclipse

A solar eclipse is when the Moon is between the Earth and the Sun, and a lunar eclipse is when the Earth is between the Moon and the Sun.

Warmer atoms expand. There is also more movement. This is also explained when putting it into terms with solid vs. gas. in a solid, the atoms vibrate, but they can't move very far because there is not a lot of space between them. In a gas, on the other hand, the atoms are spread apart, and they move very fast. Putting it into context with water, the steam (gas) version is hot, and the ice cube (solid) version is cold.