Question 1: Explain what is meant by the term 'alkali metal' and describe one key characteristic of elements in Group 1.

Answer: Alkali metals are elements in Group 1 of the periodic table that are highly reactive metals characterised by having a single electron in their outermost shell.

Question 1: Describe how the reactivity of alkali metals changes as you move down Group 1 from lithium to francium.

Answer: The reactivity increases down the group because the outer electron becomes easier to lose as the atomic radius increases, reducing the electrostatic attraction between the nucleus and the outer electron.

Question 2: Calculate the number of moles in 3 grams of sodium (Na). (Atomic mass of Na = 23 g/mol)

Answer: Number of moles = mass / molar mass = 3 / 23 ≈ 0.130 moles

Question 1: Design a simple experiment to demonstrate the reactivity of lithium with water. Include the variables involved and safety precautions.

Answer: The experiment involves placing a small piece of lithium metal into a container of water and observing the reaction. Variables include the amount of lithium and water temperature. Safety precautions include wearing safety goggles, gloves, and conducting the experiment in a well-ventilated area away from sources of ignition, as the reaction produces hydrogen gas and heat.

Question 1: A student observes that when potassium reacts with water, the reaction is more vigorous than with sodium. Explain why potassium shows greater reactivity based on atomic structure.

Answer: Potassium has a larger atomic radius and its outer electron is further from the nucleus, making it easier to lose and thus increasing its reactivity compared to sodium.

Question 2: A sample of alkali metal reacts with water to produce 2.0 litres of hydrogen gas at room temperature and pressure. Calculate the number of moles of hydrogen gas produced. (Use 1 mol of gas = 22.4 litres at RTP)

Answer: Number of moles = volume / molar volume = 2.0 / 22.4 ≈ 0.0893 moles

Question 1: Discuss how alkali metals are used in industry, providing at least one example of a specific application.

Answer: Alkali metals like sodium are used in the manufacturing of glass through the addition of sodium carbonate, which lowers the melting point of silica and improves the process.

Question 2: Identify safety considerations when handling alkali metals in industrial settings.

Answer: Handling alkali metals requires precautions such as storing under oil to prevent moisture contact, wearing protective equipment, and using proper containment to avoid fires or explosions due to their high reactivity, especially with water or air.