Atoms, Elements, and Compounds

1. Which statement best describes an element?

• made from mixture

• thousands in the world

• pure, made of only one atom

• can be separated

2. The smallest particle of any particular type of matter is known by which of the following terms?

 

 

 

• Element

• Chemical

• Atom

3. Which of the following elements has the INCORRECT symbol?

• Ca – Calcium

• CO – Copper

• O – Oxygen

• Ar- Argon

4. Oxygen gas has a formula of O₂, is this  an atom or a molecule?

• Atom

• Molecule

5. How many hydrogen atoms are present in one molecule of water (H₂O)?

• 1

• 2

• 3

6. Water (H₂O) is an element

• True

• False

7. Hydrogen  is considered an element while water (H₂O) is considered a compound. This is because water is –

• a gas at room temperature.

• made of two different elements.

• given off by green plants.

8. What do we call a chemical substance made up of 2 or more different types atoms bonded together?

• formula

• atom

• subscript

• compound

9. All ____________ are made up of two or more atoms bonded together.

• atoms

• molecules

• electrons

   

• elements

10. Is hydrogen gas (H₂) a compound?

• Yes, it is a compound because it has 2 atoms present.

   

• No, because there is only one type of atom present.