Matter

What are all things made of?

• matter

• atoms

• both are true

What do pure gold and pure iron have in common?

• They are both compounds.

• They are made up of a single element.

hydrogen and oxygen bond to form a molecule of water. What does the word bond mean in this sentence?

• Move in circles around one another.

• Make more copies of themselves.

• Share something and join together.

• split apart from each other.

What are the three kinds of particles inside an atom?

• hydrogen, oxygen, and helium

• electrons, protons, and neutrons

• elements, compounds, and molecules

Scientists identify an ammonia molecule as NH3. How many atoms of hydrogen does it have?

• 4

• 3

• 1

• There is not enough information to determine the answer.

If two atoms of hydrogen join together, they form

• an element

• a compound

• a mixture

Pure substances can be classified as

• matter and molecules

• homogeneus mixtures and heterogeneous mixtures

• elements and compounds

• substances and mixtures

Elements are made of

• two or more equal atoms

• two or more different atoms