What is the term for magma that erupts onto earth's surface?
steam
debris
obsidian
lava
Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000 o C. When magma erupts onto Earth’s surface, it is known as lava ( Figure below ). Minerals form when magma and lava cool. Some minerals crystallize at hotter temperatures. These minerals form first. Other minerals form at cooler temperatures. These minerals form later.