1. CHEMISTRY DEPARTMENT WAID ACADEMY Standard Grade Topic 4

2. Which of the following gives the best description of the molecule shown? 1.A molecule of oxygen with a double covalent bond is shown. 2.A molecule of hydrogen with a single covalent bond is shown. 3.A molecule of nitrogen with a triple covalent bond is shown. 4.A molecule of fluorine with a single covalent bond is shown. :15

3. Which of the elements shown below will conduct electricity when solid? 1.Sulphur. 2.Silicon. 3.Argon. 4.Carbon. :12

4. Which the substances shown below has a covalent lattice structure? :15 1.Sulphur dioxide. 2.Silicon. 3.Sulphur. 4.Magnesium chloride.

5. Which of the following correctly describes a molecule made up of two atoms? 1.Double covalent. 2.Diatomic. 3.Di-molecular. 4.Monatomic. :12

6. Which of the following shows three elements which all exist as diatomic molecules? 1.Hydrogen, fluorine and bromine. 2.Oxygen, sulphur and chlorine. 3.Nitrogen, phosphorus and sulphur. 4.Helium, neon and argon. :12

7. Which of the substances shown has ions in an ionic lattice? 1.Phosphorus. 2.Carbon (diamond). 3.Lead. 4.Magnesium chloride. :12

8. What is the valency of phosphorus? 1.2. 2.3. 3.4. 4.5. :12

9. Which box shows the formula for calcium carbide? 1.CaC 2. 2.CaC. 3.Ca 2 C 4. 4.Ca 2 C. :15

10. Which formula shown is the correct formula for dinitrogen monoxide? 1.NO 2. 2.N 2 O 2. 3.N 2 O. 4.NO :15

11. Which of the substances shown below will conduct electricity? 1.Solid copper sulphate crystals. 2.Molten sulphur. 3.Solid candle wax. 4.Molten lead iodide. :15

12. End of test