Elements

What is the element symbol for...

1. Hydrogen.

2. Magnesium

3. Iron.

4. The list on the right shows 6 substances. Which one is not an element?

5. Na and Au are both elements. Which of these answers gives the correct elements for these symbols?

6. Which of these is the best description for a compound?

• A. A substance made of one element only.
• B. A substance made of two or more elements mixed together.
• C. A substance made of one element, but with atoms joined together.
• D. A substance made of two or more elements joined together.

7. Which of these is the best description for a molecule?

• A. A single atom.
• B. Two or more atoms joined together.
• C. Two or more elements mixed together.
• D. Part of an atom.

8-10. Here is a picture of chlorine gas. Two chlorine atoms are joined together.

8. The diagram above shows..

• A. an atom of an element.
• B. an atom of a compound.
• C. a molecule of an element.
• D. a molecule of a compound.

9. How is this written down in symbols?

• A. Cl²
• B. Cl2
• C. 2Cl
• D. Cl₂

10. Chlorine is element number 17. What is element number 1?

• A. Hydrogen.
• B. Helium.
• C. Oxygen.
• D. Carbon