1. CHEMISTRY DEPARTMENT WAID ACADEMY Unit 1 Susbstances

2. Approximately how many elements are there? 1.About 50 2.About 80 3.About 100 4.About 125 12

3. What is the symbol for the element sodium? 15 1.S 2.Si 3.Se 4.Na

4. What is the name of the element which has the symbol Ca? 15 1.Carbon 2.Calcium 3.Copper 4.Caesium

5. Which of the elements shown is a liquid at room temperature? 12 1.Silicon 2.Oxygen 3.Magnesium 4.Bromine

6. Which line shows three substances, all of which are gases at room temperature? 15 1.Hydrogen, oxygen and helium. 2.Hydrogen, oxygen, and bromine. 3.Mercury, oxygen and sulphur. 4.Oxygen, nitrogen and bromine.

7. Which of the elements shown is a non-metal? 20 1.Potassium. 2.Cobalt. 3.Chromium. 4.Phosphorus.

8. Which line shows three elements which have been known for a very long time? 20 1.uranium, americium and radium. 2.gold, silver and plutonium. 3.copper, silver and gold. 4.americium, gold and lead.

9. Which line shows three elements which all belong to the Noble Gas group of elements? 12 1.lithium, sodium and potassium 2.fluorine, chlorine and bromine 3.hydrogen, oxygen and nitrogen 4.helium, neon and argon

10. Which compound contains three elements, one of which is oxygen? 12 1.sodium oxide 2.sodium carbonate 3.sodium nitride 4.sodium hydride

11. A gas relights a glowing splint. Which gas is this? 12 1.Oxygen 2.Hydrogen 3.Nitrogen 4.Carbon dioxide