Worksheet Chapter 4: The Periodic Table of Elements

1. Explain why Argon exists as a monatomic gas and does not form chemical bonds under normal conditions.

2. State two catalytic applications of transition elements in industrial processes.

3. Chlorine, Bromine, and Iodine are elements in Group 17.
(a) State the trend in physical state and color going down from Chlorine to Iodine.
(b) Write a balanced chemical equation for the reaction between Chlorine gas and hot iron wool.
(c) State one safety precaution when conducting experiments involving halogens in the laboratory.

4. True or False: Reactivity of Group 17 halogens increases as you move down the group.

5. Elements P and Q have proton numbers of 11 and 17 respectively.
(a) Write the electron arrangement for P and Q.
(b) State the group and period for element Q in the Periodic Table.

6. True or False: The atomic radius decreases from left to right across Period 3.

7. Fill in the blank: The horizontal rows in the Periodic Table are called ________.

8. Which element in Period 3 forms an oxide that reacts with BOTH hydrochloric acid and sodium hydroxide solution?

9. Describe an experiment to demonstrate the amphoteric property of aluminium oxide (Al2O3) using chemical equations.

10. Compare the reactivity of Sodium (Na) and Potassium (K) when reacting with water. Explain your answer based on atomic structure.