Question 1: Describe the general physical properties of Alkali Metals (Group 1 elements).

Answer: Alkali Metals are soft, shiny, and silvery in appearance. They are good conductors of heat and electricity and have low melting points compared to most metals.

Question 2: Explain why Alkali Metals are highly reactive, especially with water.

Answer: Alkali Metals have a single outer electron which they readily lose to form positive ions, making them highly reactive, particularly with water which facilitates electron transfer.

Question 1: Define the term 'alkali metal'.

Answer: An alkali metal is a soft, silvery metal belonging to Group 1 of the Periodic Table that reacts vigorously with water and air.

Question 2: What is the trend in reactivity of Alkali Metals as you move down Group 1? Explain your answer.

Answer: Reactivity increases as you move down Group 1 because the outer electron is farther from the nucleus, making it easier to lose and thus increasing reactivity.

Question 1: Calculate the number of moles in 11.2 grams of sodium (Na). (Molar mass of Na = 23 g/mol)

Answer: 0.488 mol

Question 2: If 0.1 mol of potassium reacts with water, how many grams of potassium are involved? (Molar mass of K = 39 g/mol)

Answer: 3.9 g

Question 1: Describe a safe method to demonstrate the reaction of sodium with water in a school laboratory, including safety precautions.

Answer: A small piece of sodium should be cut and placed in a test tube with a small amount of water, wearing safety goggles and gloves. The experiment should be conducted in a well-ventilated area or fume cupboard, away from flames or heat sources, as the reaction produces hydrogen gas which is flammable.

Question 2: Identify the independent variable in the experiment where sodium reacts with water.

Answer: The type or amount of Alkali Metal used.

Question 1: A student observes that lithium reacts more vigorously with water than sodium. Explain this observation based on atomic structure and reactivity principles.

Answer: Lithium is higher up in Group 1, meaning its outer electron is closer to the nucleus and less shielded, but still, the reactivity trend generally increases down the group. If lithium reacts more vigorously, it could be due to experimental conditions, but normally, sodium reacts more vigorously than lithium because the larger atomic size and more easily lost outer electron make sodium more reactive.

Question 1: Name one common application of sodium and explain why it is suitable for this purpose.

Answer: Sodium vapour lamps are used in street lighting because sodium emits a bright yellow light that is visible over long distances and is energy efficient.

Question 2: Explain how lithium is used in the manufacture of rechargeable batteries and why it is ideal for this purpose.

Answer: Lithium is used in rechargeable batteries because it has a high electrochemical potential, low density, and can store a large amount of energy in a small space. Its ability to undergo reversible reactions makes it ideal for battery technology.

Question 1: Summarise the key properties and reactivity trends of Alkali Metals, and discuss their importance in industry and daily life.

Answer: Alkali Metals are soft, silvery, highly reactive metals with low melting points. Their reactivity increases down the group due to larger atomic size and electron shielding. They are important in industry for applications like lighting, batteries, and chemical manufacturing, and in everyday life for products such as table salt, medicines, and cleaning agents.