Understanding Materials and Their Types

What are thermoplastics and how do they differ from thermosetting plastics?

• Thermoplastics are always rigid and cannot be reshaped.

• Thermoplastics are used only for electrical insulation applications.

• Thermosetting plastics can be melted and reshaped multiple times.

• Thermoplastics can be remelted and reshaped, while thermosetting plastics cannot be remelted after curing.

Name two common examples of thermoplastics.

• Polyurethane

• Polyethylene, Polypropylene

• Polystyrene

• PVC

What is a characteristic property of thermosetting plastics?

• They are always flexible and soft.

• They cannot be remolded or reshaped after curing.

• They can be easily reshaped multiple times.

• They dissolve in water easily.

List two types of hardwood commonly used in furniture making.

• cedar, pine

• oak, maple

• birch, pine

• pine, oak

What is the main difference between hardwood and softwood?

• Hardwood is used exclusively for furniture, while softwood is not.

• The main difference is that hardwood comes from deciduous trees and is denser, while softwood comes from coniferous trees and is generally lighter.

• Softwood comes from deciduous trees and is denser.

• Hardwood is always lighter than softwood.

Give one example of a softwood tree.

• Oak

• Pine

• Maple

• Birch

What are ferrous metals and what is their main characteristic?

• Ferrous metals are metals that contain aluminum and are non-magnetic.

• Ferrous metals are metals that do not contain iron and are resistant to rust.

• Ferrous metals are metals that contain iron, and their main characteristic is that they are magnetic and susceptible to rust.

• Ferrous metals are metals that are only found in nature and cannot be manufactured.

Name one example of a non-ferrous metals.

• Iron

• Lead

• Zinc

• Aluminum

What is the significance of the term 'alloy' in metals?

• Alloys improve the properties of metals for various applications.

• Alloys are only used for decorative purposes.

• Alloys are pure metals without any additives.

• Alloys decrease the strength of metals.

How does the density of hardwood compare to softwood?

• Hardwood is lighter than softwood.

• Hardwood and softwood have the same density.

• Softwood is denser than hardwood.

• Hardwood is denser than softwood.