Question 1: Define Alkali Metals and list three common elements in Group 1 of the periodic table.

Answer: Alkali Metals are highly reactive metals in Group 1 of the periodic table, including Lithium, Sodium, and Potassium.

Question 2: Explain why Alkali Metals are useful in forensic science for analyzing evidence.

Answer: Because they react strongly with certain substances, producing detectable changes, which can help identify substances at a crime scene.

Question 3: What safety precautions should be taken when handling Alkali Metals in a laboratory setting?

Answer: Wear protective gloves and goggles, work in a fume hood, and handle the metals with appropriate tools to prevent reactions with moisture or skin.

Question 4: Describe a typical forensic scenario where Sodium's reactivity could be used to identify evidence.

Answer: In a forensic investigation, Sodium can be used to test for the presence of certain acids or compounds by observing its reaction, such as the production of a characteristic flame color or gas.

Question 5: Calculate the number of moles in 10 grams of Sodium. (Atomic mass of Na = 23 g/mol)

Answer: Number of moles = mass (g) / atomic mass (g/mol) = 10 g / 23 g/mol ≈ 0.435 mol

Question 6: Which of the following elements is NOT an Alkali Metal? A) Lithium B) Calcium C) Potassium D) Cesium

Answer:

Question 7: Fill in the blank: Alkali Metals are known for their high reactivity due to having ________ electrons in their outermost shell.

Answer: one

Question 8: Explain how the reactivity of Alkali Metals changes down the group and why.

Answer: Reactivity increases down the group because atoms have more electron shells, which makes it easier for the outermost electron to be lost, increasing reactivity.

Question 9: Identify a forensic application where Potassium ions are used to determine the presence of biological evidence.

Answer: Potassium ions are used in chemical tests to identify biological fluids like blood, which contain potassium, through specific chemical reactions.

Question 10: Discuss the environmental impact of improper disposal of Alkali Metals after forensic use.

Answer: Improper disposal of Alkali Metals can lead to environmental pollution, including water contamination and harm to wildlife, due to their high reactivity and potential to release toxic compounds when they react with water or other substances.