1. The chemical symbol for potassium is

A. Po

B. P

C. K

D. Pt

2. The atomic number of an element is the number of

A. neutrons

B. electrons

C. protons

D. nucleons

3. Which of these is a noble gas?

A. Nitrogen

B. Neon

C. Oxygen

D. Hydrogen

4. The formula for calcium hydroxide is

A. CaOH

B. Ca(OH)₂

C. Ca₂OH

D. CaO₂H

5. Which of the following is not a mixture?

A. Air

B. Sand and salt

C. Water

D. Salt water

6. The gas used in the preparation of soda water is

A. Oxygen

B. Hydrogen

C. Nitrogen

D. Carbon dioxide

7. Which of the following is a chemical change?

A. Melting of ice

B. Boiling of water

C. Burning of paper

D. Dissolving of salt

8. Which of the following is used to test for the presence of water?

A. Cobalt chloride paper

B. Red litmus paper

C. Blue litmus paper

D. Sodium hydroxide

9. The most electropositive element is

A. Hydrogen

B. Potassium

C. Calcium

D. Francium

10. Which of the following is a base?

A. HCl

B. NaOH

C. CO₂

D. CH₄

(a)