Question 1: Metals are elements that typically have high melting points, are good conductors of heat and electricity, and are malleable. Non-metals have properties opposite to metals, such as being poor conductors and brittle. Based on these properties, classify the following elements as metals or non-metals: Aluminum, Sulfur, Iron, Carbon.

Answer: Aluminum - Metal; Sulfur - Non-metal; Iron - Metal; Carbon - Non-metal

Question 1: Define the term 'metalloid' and give an example.

Answer: A metalloid is an element that has properties of both metals and non-metals. Example: Silicon.

Question 2: Explain why metals are generally found on the left side of the periodic table, while non-metals are on the right.

Answer: Metals are on the left because they tend to lose electrons to form positive ions, and their atomic structure favors this. Non-metals are on the right because they tend to gain electrons to form negative ions.

Question 1: Calculate the number of neutrons in an atom of Carbon-14. (Atomic number of Carbon = 6; Atomic mass = 14 u).

Answer: 8 neutrons (14 - 6 = 8)

Question 2: If an element has 16 protons and 16 electrons, what is its atomic number and charge?

Answer: Atomic number = 16; Charge = neutral (0)

Question 1: Describe a simple experiment to test whether a substance is a metal or a non-metal based on conductivity.

Answer: Connect the substance to a circuit with a light bulb and a battery. If the bulb lights up, the substance conducts electricity and is likely a metal. If not, it is likely a non-metal.

Question 2: List two safety precautions to consider when handling metals in the laboratory.

Answer: Wear gloves and safety goggles; handle hot metals with tongs.

Question 1: A sample of element X has a melting point of 660°C and forms positive ions easily. Is element X likely a metal or non-metal? Explain your reasoning.

Answer: It is likely a metal because of its high melting point and tendency to form positive ions.

Question 2: An element is found to be brittle and a poor conductor of electricity. Based on these properties, classify it as a metal or non-metal.

Answer: It is a non-metal.

Question 1: Describe the main differences between metals and non-metals in terms of their physical and chemical properties. (6 marks)

Answer: Metals are generally shiny, malleable, ductile, good conductors of heat and electricity, and tend to lose electrons during reactions. Non-metals are dull, brittle, poor conductors, and tend to gain electrons during chemical reactions.

Question 1: Explain why aluminum is widely used in the construction of aircrafts.

Answer: Because aluminum is lightweight, strong, resistant to corrosion, and a good conductor of heat and electricity.

Question 2: Identify a non-metallic element used in industry for its insulating properties and describe its application.

Answer: Sulfur is used in the production of sulfuric acid, which is essential for manufacturing fertilizers and in chemical industries.