Acids & Metals

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How other metals react with acids?

Metals all similar physical properties: shiny, conduct heat and electricity. Metals have similarities in chemical properties. magnesium + hydrochloric acid→ magnesium chloride + hydrogen. this is called a displacement reaction when the more reactive substance take the less reactive substance's place.

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Metals and Oxygen

magnesium + oxygen→ Magnesium oxide

2M + O2→ 2MgO

Not all metals react in this way for example gold is unreactive with oxygen we can tell the reactivity by using the reactivity scale:

Potassium, Sodium, Lithium, Calcium ,Magnesium, Aluminium, Zinc, Iron, Tin, Lead, Copper, Silver, Gold, Platinum.

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Metals and Water

Some metals don't react with water. The group 1 metals react vigorously with water. When a reactive metal reacts with water it creates metal hydroxide and hydrogen.

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Extracting Metals

What's an ore?

An ore is a rock that you can extract metal from e.g. iron ore is a mixture of compounds with iron. the metals are extracted from the ore is using a more reactive metal to displace the metal you want (using the displacement reaction). You could also use carbon for some metals.

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Ceramics

Properties:

Hard

Brittle

Stiff

Solid at room temp

Electrical insulators

Don't react with water, acids or alkalis

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Polymers

Natural Polymers: They come from plants and animals. Wool traps heat, cotton is strong and durable and rubber is flexible and durable.

Synthetic: These are made using chemical reactions. There are hundreds of synthetic polymers, each polymer has it's own properties.

Poly(ethene)

The molecules in the low density polyethene (LDPE) slide over each other. This makes it flexible but strong.

High density polyethene is also strong and flexible however it's harder.

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Composites

Reinforced concrete is a composite material. A composite material is a mixture of materials. The properties of composites are combined of those materials used to make it. Different composites have different properties, for different purposes.

Examples of Composites:

• Carbon fibre

• Plywood

• Reinforced concrete