Select the one substance that is not a rock.
Conglomerate is not made by living things. It is formed in nature. An eggshell is made by a living thing. It is a solid. Pumice is not a pure substance. It is not made by living things.
Rocks are made of minerals. Here are some properties of rocks:
They are solid.
They are formed in nature.
They are not made by living things.
They are not pure substances.
Compare the properties of each substance to the properties of rocks. Select the substance whose properties do not match those of rocks.
Conglomerate is a rock.
An eggshell is made by a living thing. But rocks are not made by living things.
So, an eggshell is not a rock.
Pumice is a rock.