Identifying Metals and Non-Metals
Which group does copper belong to: metals or non-metals?
Answer: Copper is a metal. It is shiny, conducts electricity well, and can be made into wires.
What is meant by the term lustre?
Answer: Lustre refers to how shiny or reflective a material appears.
Where are most metals located on the periodic table?
Answer: Most metals are located on the left side and centre of the periodic table.
Why is copper commonly used in electrical wires?
Answer: Copper is used because it conducts electricity very well and is ductile enough to be made into wires.
What is an alloy?
Answer: An alloy is a material made by combining a metal with one or more other elements to produce useful properties. Examples include steel and stainless steel.
Name two properties that are commonly found in metals.
Answer: Any two of:
Which property allows a material to be hammered into sheets?
Answer: Malleability.
Where are most non-metals located on the periodic table?
Answer: Most non-metals are located on the upper right side of the periodic table.
Why is aluminium often chosen when low weight is important?
Answer: Aluminium has a relatively low density, making it lightweight.
What is a composite material?
Answer: A composite material is made from two or more different materials that work together to provide useful properties.
Explain one difference between metals and non-metals in terms of electrical conductivity.
Answer: Metals generally conduct electricity well, while most non-metals are poor electrical conductors.
Which property allows a material to be drawn into wires?
Answer: Ductility.
What makes hydrogen unusual compared with many other elements on the left side of the periodic table?
Answer: Hydrogen is found on the left side of the periodic table, but it is a non-metal
Why might plastic or rubber be placed around electrical wires?
Answer: Plastic and rubber are poor electrical conductors, so they help prevent electric shocks and improve safety. This is an application based on the conductivity concepts discussed in the lessons.
Give one advantage of steel and one advantage of stainless steel.
Answer:
A substance is dull, brittle and does not conduct electricity well. Would it most likely be a metal or a non-metal?
Answer: It is most likely a non-metal because non-metals are often dull, brittle, and poor conductors of electricity
Compare malleability and ductility. How are they similar and how are they different?
Answer: Both properties describe a material's ability to change shape without breaking. Malleability is the ability to be hammered into sheets, while ductility is the ability to be drawn into wires.
What are metalloids and where are they generally found on the periodic table?
Answer: Metalloids are elements that have a mixture of metallic and non-metallic properties. They are found near the zigzag boundary between metals and non-metals
A company needs a material for a bicycle frame. Would aluminium or steel be a better choice?
Answer: Aluminium may be chosen because it is lightweight, making the bicycle easier to ride. A disadvantage is that it may not be suitable for every high-load structure. Steel is stronger but heavier and may rust.
Fibreglass is a composite material. Describe how its different materials work together.
Answer: Fibreglass contains glass fibres embedded in a plastic material. The glass fibres provide strength and reinforcement, while the plastic holds the fibres together.
A student finds a shiny material that conducts electricity poorly and breaks when struck. Explain why using only one property could lead to an incorrect classification and suggest how the student could improve their conclusion.
Answer: Using only one property, such as shininess, can be misleading because appearance alone does not determine whether a substance is a metal or non-metal. The student should test several properties such as conductivity, malleability, ductility, and brittleness before making a conclusion.
A manufacturer needs a material for electrical cables that can carry electricity and be shaped into long wires. Identify two important properties and explain why they are important.
Answer:
A newly discovered element is found near the zigzag boundary of the periodic table. Predict what type of properties it may have and explain your reasoning.
Answer: The element may have both metallic and non-metallic properties because elements near the zigzag boundary are metalloids. It might conduct electricity better than most non-metals but not as well as most metals
A community is designing a new outdoor shelter. Recommend a material for the main structure and justify your choice.
Answer: Steel would be a good choice because it is strong and durable. However, it may rust over time. To improve the design, protective coatings or corrosion-resistant materials could be used
Engineers must choose between stainless steel and fibreglass for a structure near the coast. Compare the advantages and disadvantages of each material and recommend the best choice.
Answer:
Stainless steel
Fibreglass
Recommendation: Stainless steel would generally be the better choice because its corrosion resistance makes it more suitable for coastal conditions.