The answers would be:
1. Core = Earth's internal energy and magnetic field
2. Mantle = Where convection currents circulate, driving plate tectonics.
3. Crust = Where tectonic plates collide, spread, and rub, creating surface features and events, like volcanoes and earthquakes.
Here's more about the layers of the Earth:
The crust, among all the layers, is the thinnest layer of Earth. It is the outermost layer and it is basically where we live. The crust is divided into rigid tectonic plates and it is in their boundaries where geological activities occur.
The mantle on the other hand, is the thickest layer among all the layers. The convection currents that occur here is what drive tectonic plates. As magma found in this layer gets heated by the core within, it rises and moves to upwards. As it is cooled when it moves away from the heat source, it moves back down and heats up again. This creates convection currents that drag the tectonic plates.
The core has two layers, the inner core and the outer core. The core is made up mostly of iron. The inner core is solid because of the immense pressure caused by gravity, while the outer core is more liquid. It is because of the flow of liquid iron in the outer core the Earth's magnetic field is produced.