What causes volcanoes to erupt when pressure builds up inside the Earth?

A volcano erupts when pressure inside the Earth gets too big and has to come out like a balloon popping.

Imagine you have a big bottle filled with soda. The soda is like magma, which is hot liquid rock deep inside the Earth. When you shake the bottle, bubbles form, just like how gas forms in magma. These bubbles are like gas trapped inside the Earth. As more bubbles build up, they push against the top of the bottle, making it tighter and tighter, just like how pressure builds up under a volcano.

If you keep shaking that soda bottle, eventually the pressure becomes too much, and plop! The lid flies off, and soda sprays everywhere. That’s like what happens with a volcano. The Earth's top, called the crust, acts like the lid of the bottle. When the pressure gets too high, it cracks open, and out comes the hot lava, gas, and ash.

Sometimes, it’s not just soda, imagine shaking up a whole can of fizzy drink and then popping the cap off! That's how volcanoes feel when they erupt, excited and full of energy, ready to let everything go.