What is lava?

Lava is defined as molten rock that is expelled from a volcano during an eruption and is found on the surface of the Earth. When volcanic material erupts, it flows out of the volcano and is known as lava. This process occurs when magma, which is molten rock located beneath the Earth's surface, makes its way to the surface through volcanic vents. Once it erupts and reaches the surface, it begins to cool and solidify, distinguishing it from magma, which is the term used for molten rock that remains underground.

The other options do not accurately describe lava: molten rock on the moon's surface refers to geological phenomena specific to a different celestial body and not Earth. Molten rock beneath the Earth's surface is called magma, not lava. Solidified magma is what we refer to as igneous rock, which is the end product of the cooling of magma or lava. Thus, understanding these distinctions helps clarify why molten rock on the Earth's surface is specifically termed "lava."