Science 7 · Unit 2: Materials and their structure · Cambridge Lower Secondary Science Stage 7

Questions

1. 1. True or false: Each element is made of only one type of atom.

   • True
   • False
   Check

2. 2. Is oxygen an element or a compound?

   • a compound
   • neither
   • a mixture
   • an element
   Check

3. 3. True or false: Calcium is an element.

   • True
   • False
   Check

4. 4. True or false: water is an element.

   • True
   • False
   Check

5. 5. A diagram shows several neon atoms that are not joined to anything. True or false: it shows a compound of neon.

   • True
   • False
   Check

6. 6. What is a compound?

   • a substance made of only one kind of atom
   • two substances mixed but not joined
   • any substance that is a liquid
   • a substance made of two or more different kinds of atom bonded together
   Check

7. 7. What is the chemical word for atoms joining tightly together?

   • bonding
   • melting
   • dissolving
   • mixing
   Check

8. 8. A particle diagram shows two oxygen atoms joined together. What does this show?

   • a compound, because oxygen is a gas
   • a mixture, because there are two atoms
   • a compound, because two atoms are joined
   • an element, because both atoms are the same kind
   Check

9. 9. Which formula shows a compound?

   • Al
   • O₂
   • H₂
   • CaCl₂
   Check

10. 10. Sodium is a soft, shiny metal that reacts with water. Chlorine is a poisonous green gas. What is sodium chloride like?

    • a green metal that reacts with water
    • a poisonous green gas
    • a soft, shiny metal
    • a white solid that we can eat as salt
    Check

11. 11. When a metal and a non-metal form a compound, how is it named?

    • The metal comes first, and the non-metal's name changes, often to end in -ide.
    • The non-metal comes first, and the metal's name ends in -ide.
    • The two names are joined with 'and'.
    • The element with the shortest name comes first.
    Check

12. 12. Which elements are in potassium chloride?

    • potassium and chlorine
    • potassium, chlorine and oxygen
    • potassium and carbon
    • phosphorus and chlorine
    Check

13. 13. Which is the metal in potassium chloride?

    • potassium
    • both of them
    • chlorine
    • chloride
    Check

14. 14. Which elements are in magnesium oxide?

    • magnesium and oxygen
    • magnesium, oxygen and hydrogen
    • manganese and oxygen
    • magnesium only
    Check

15. 15. Suggest the name of the compound that contains copper and oxygen.

    • oxygen copperide
    • copper oxygen
    • copper oxidate
    • copper oxide
    Check

16. 16. Suggest the name of the compound that contains iron and chlorine.

    • chlorine iron
    • iron chlorate
    • iron chlorine
    • iron chloride
    Check

17. 17. What is the name of the compound of sodium and oxygen?

    • sodium oxide
    • sodium oxidate
    • sodium oxygen
    • oxygen sodide
    Check

18. 18. What is the name of the compound made from calcium, carbon and oxygen?

    • calcium carbon oxide
    • carbon calcium oxide
    • calcium carbide
    • calcium carbonate
    Check

19. 19. What is the name of the compound formed when potassium, nitrogen and oxygen are combined?

    • nitrogen potasside
    • potassium nitride
    • potassium nitrogen oxide
    • potassium nitrate
    Check

20. 20. What is the name of the compound of potassium and nitrogen?

    • potassium nitrogen
    • potassium nitride
    • nitrogen potasside
    • potassium nitrate
    Check