1. The Earth's Mantle: The mantle is a layer of hot, semi-solid rock beneath the Earth's crust. Heat from the Earth's core causes the mantle to heat up. Hotter, less dense rock rises, while cooler, denser rock sinks. This creates a circular flow known as mantle convection. This process is responsible for plate tectonics, driving the movement of continents and causing earthquakes and volcanic eruptions.

2. The Atmosphere: The Sun's energy warms the Earth's surface, causing air to heat up and rise. Cooler, denser air from higher altitudes descends to replace the rising air. This process creates atmospheric convection currents, which are responsible for weather patterns, wind, and the formation of clouds.