The outer core is made of liquid rocks, so it's very hot. The inner core is made of solid rocks. The Earth has seven plates that move a little bit every year. When the plates rub and crash into each other, it makes an earthquake. Sometimes earthquakes are small, but sometimes they are big, and makes a lot of damage.
Volcanoes often erupt at the same time as an earthquake.
Volcanos shoot hot rocks into the air. The Earth is very interesting to me.