8th Grade Science Practice SOL 2010

Front

What is an element in chemistry?

Back

A substance that cannot be broken down into simpler substances by chemical means.

Front

How many elements are involved in a chemical reaction if the answer is 3?

Back

There are three different elements involved.

Front

What is the mesosphere?

Back

The layer of Earth's atmosphere above the stratosphere, characterized by decreasing temperatures with altitude.

Front

What is the stratosphere?

Back

The layer of Earth's atmosphere above the troposphere, containing the ozone layer and characterized by increasing temperatures with altitude.

Front

What is the difference between the mesosphere and the stratosphere?

Back

The mesosphere contains fewer oxygen molecules than the stratosphere.

Front

What is an estuary?

Back

A coastal area where freshwater from rivers meets and mixes with saltwater from the ocean.

Front

Why is water known as the 'universal solvent'?

Back

Because it dissolves the greatest number of substances compared to other solvents.

Front

What is an independent variable in an experiment?

Back

The variable that is changed or controlled in a scientific experiment to test its effects on the dependent variable.

Front

In an experiment measuring how much of a substance dissolves in water, what is the independent variable?

Back

Water temperature.

Front

What is the dependent variable in an experiment?

Back

The variable that is measured and affected in the experiment.