Calcium

chemistry · elements · bones

Builds your bones. Calcium is the main ingredient that makes your skeleton hard and strong. Without eating enough calcium from foods like milk and cheese, your bones can't grow properly.

Fifth most abundant element. Calcium is one of the most common elements in Earth's crust, beaten only by oxygen, silicon, aluminum, and iron. It's everywhere around you in rocks and soil.

Found in limestone and chalk. The most common calcium compound on Earth is calcium carbonate, which forms limestone, chalk, and the hard shells of sea creatures. Long ago, these shells piled up and turned into the rocks we see today.

Reactive and shiny. Calcium is a metal that's so reactive it gets a dark coating when it touches air. This happens because calcium is always eager to combine with other substances.

Named from Latin. The word calcium comes from the Latin word 'calx,' which people got by heating limestone. Roman people knew about this substance thousands of years ago.