CLASSIFICATION OF ROCKS / LESSON 2

Earth´s crust is made of ____________ .

• mountains

• rocks

• cliffs

• water

It can take ____________ of years for some rocks to form .

• several

• few

• some

• millions

Scientists base the classification of rocks on the way they are ______________ .

• formed

• based

• selected

• piled

The changes that form rocks produce three main kinds of rocks : igneous, sedimentary and _______________ rocks.

• volcanic

• metamorphic

• cliff

• underground

Some rocks form from other rocks that have ___________ .

• erupted

• collapsed

• melted

• broken

The melted rock is called ____________ .

• graffite

• gold

• magma

• silver

Rocks that form from molten rock are called ____________ rocks .

• metamorphic

• sedimentary

• underground

• igneous

_________ rocks may form above or below Earth´s surface .

• Igneous

• Sedimentary

• Metamorphic

• Volcanic

The molten rock after a volcano erupts is called ________ .

• sediment

• gold

• lava

• magma

When lava cools, mineral ___________ form .

• magnets

• particles

• rocks

• crystals