Chapter 2 Review

An element...

• contains many different kinds of atoms.

• contains only one kind of atom.

• contains molecules.

• None of the above

Sarah uses a compass in her house and the needle points north. When she crosses the street and stands inside Chloe’s house, which direction will the needle point?

• east

• west

• north

• south

When a battery is placed inside a device, it becomes

• a. a metal.

• b. a chemical substance.

• c. an acid.

• d. part of an electrical circuit.

When a substance is heated, its atoms and molecules

• stop moving.

• move more quickly.

• break apart.

• stick together.

Fill in the blanks in each sentence below. 5. Everything in the world is made of millions of tiny _____________________.

• atoms

• cells

• molecules

• rocks

Fill in the blanks in each sentence below. ____________________ is an example of a conductor, and ____________________ is an example of an insulator.

• Copper & Rubber

• Wood & Glass

• Plastic & Iron

• Gold & Copper

Fill in the blanks in each sentence below. To magnetize a metal paperclip, you could rub it with ____________________.

• a magnet

• a pencil

• a piece of paper

• a plastic spoon

Human beings breathe out carbon dioxide. Its chemical formula is CO₂. The C stands for carbon, and the O stands for oxygen.

CO₂ is an atom?

• True

• False

Every molecule of carbon dioxide contains carbon and oxygen atoms.

• True

• False

People who work with electricity wear rubber gloves because:

• rubber is an insulator and prevents electric shock

• rubber gloves are comfortable to wear

• rubber gloves improve grip on tools

• rubber gloves keep hands warm