Materials - Metals And Plastics

Explanation
The correct answer is Aluminium, Copper, Lead, Tin. These metals are considered non-alloy non-ferrous metals because they do not contain iron and are not mixed with other metals. Aluminium is a lightweight metal with excellent corrosion resistance. Copper is a highly conductive metal commonly used in electrical wiring and plumbing. Lead is a dense metal known for its high resistance to corrosion and radiation. Tin is a malleable metal often used as a coating for other metals to prevent corrosion.

Explanation
Zinc, brass, bronze, and duralumin are all examples of alloy non-ferrous metals. Alloy non-ferrous metals are metals that are composed of a mixture of two or more elements, with at least one of them being a metal and none of them being iron. Zinc is a commonly used alloy non-ferrous metal that is often used as a coating for other metals to prevent corrosion. Brass is an alloy of copper and zinc, known for its yellowish appearance and used in various applications such as musical instruments and plumbing fittings. Bronze is an alloy of copper and tin, known for its strength and durability, and used in sculptures, statues, and other decorative objects. Duralumin is an alloy of aluminum, copper, manganese, and magnesium, known for its lightweight and high strength, and used in the aerospace industry and in the production of aircraft structures.

Explanation
The question asks for 4 non-alloy ferrous metals. The given answer includes iron, cast iron, mild steel, medium carbon steel, and high carbon steel. All of these metals are non-alloy ferrous metals because they are primarily composed of iron and have no significant amounts of other elements added to them. Iron is the base metal, while cast iron is a type of iron that contains a higher amount of carbon. Mild steel, medium carbon steel, and high carbon steel are different grades of steel that contain varying amounts of carbon.

Explanation
The given answer correctly lists four alloy ferrous metals: stainless steel, high speed steel, tool and die steel, and high tensile steel. These metals are all alloys of iron and carbon, with the addition of other elements to enhance their properties. Stainless steel is known for its corrosion resistance, high speed steel is used for cutting tools, tool and die steel is used for making tools and dies, and high tensile steel is known for its high strength. These alloys are widely used in various industries due to their specific characteristics and properties.

Explanation
Thermoplastic refers to a type of plastic that consists of a tangle of long-chain molecules. This structure allows the material to be reshaped when heat is applied. Unlike thermosetting plastics, which are held together by rigid cross links, thermoplastics do not have a permanent shape and can be melted and remolded multiple times. This property makes thermoplastics versatile and suitable for various applications.

Explanation
Thermoset refers to a type of plastic that is made up of long-chain molecules that are held together by rigid cross links. This means that once the plastic is formed and hardened, it cannot be reshaped or melted again. The rigid cross links give thermoset plastics their strong and durable properties, making them resistant to heat, chemicals, and electricity. Unlike thermoplastics, which can be melted and reshaped multiple times, thermoset plastics are permanently set once they are formed.

Explanation
The given answer lists five examples of thermosetting plastics: epoxy resin, phenol formaldehyde, melamine formaldehyde, urea formaldehyde, and polyester resin. Thermosetting plastics are a type of polymer that, once set, cannot be melted or reshaped. They are formed through a chemical reaction that creates cross-links between the polymer chains, making them rigid and heat-resistant. These plastics are commonly used in applications where durability and resistance to heat and chemicals are required, such as in electrical insulation, automotive parts, and construction materials.

Explanation
The given answer correctly lists Acrylonitrile Butadiene Styrene (ABS) and Acrylic as two examples of thermoplastics. Thermoplastics are a type of polymer that can be melted and re-molded multiple times without undergoing any significant chemical change. ABS is a popular thermoplastic known for its strength, impact resistance, and durability, making it suitable for various applications such as automotive parts, toys, and electronic enclosures. Acrylic, also known as Polymethyl Methacrylate (PMMA), is another thermoplastic commonly used in products like signage, lighting fixtures, and medical devices due to its transparency, weather resistance, and high optical clarity.