University:
University of Cambridge
Course:
0653 IGCSE | Science - Combined
Academic year:

2023
Views:

30

Pages:

2
Author:

anon

IGCSE Coordinated Science: Properties of Metals Properties of Metals 1. Distinguish between metals and nonmetals by their general physical and chemical properties. Chemical Differences: Metals ❖ Often have 1-3 outer valence electrons ❖ Lose valence electrons quite easily. ❖ Form oxides that are basic ❖ Good reducing agents NonMetals ❖ Often have 4-8 valence electrons ❖ Gain or share valence electrons easily. ❖ Good oxidizing agents ❖ Form oxides that are acidic. Physical Differences: Metals ❖ Good electrical conductors ❖ Good heat conductors ❖ Malleable – Can be beaten into thin sheets ❖ Ductile – Is able to be stretched into wire. ❖ Mostly solid at room temperature Non-metals ❖ Poor conductor of electricity ❖ Poor conductor of heat ❖ Nonductile ❖ Solids, liquids or gases at room temperature. 2. Identify and interpret diagrams that represent the structure of an alloy. ❖ Alloys is the mixture of two or more metallic elements. ❖ As we can see in the diagram, we see two different types of atoms incoherently mixed together, without any apparent order. In GCSE, if you see this, you can almost assume that the diagram is suggesting an alloy. ❖ What makes alloys special is that since the atoms are all jumbled together of different sizes, it is much more difficult for alloy layers to slide over each other, so alloys are harder than pure metals. 3. Explain why metals are often used in the form of alloys. Metals such as Copper or iron are too soft for many uses. Therefore, these metals are often mixed with other methods to acquire make it harder. Additionally, an alloy has the properties of both metals, therefore it is beneficial when two metals can mix to negate the weaknesses of each other. Examples of Alloys used: ❖ Brass is used in electrical fittings, 70% copper and 30% zinc. ❖ Bronze is used for bearings and bells, and it often composed composed of 80% copper and 20% Tin. ❖ Duralumin is used for airplane manufacture, 96 % aluminium and 4% copper and other metals.