Metals and alloys
Pure metal- The layers of atoms can slide over each other.
Alloy- A mixture of metals. Other little attoms in the layers disrupt the rows making it so the layers cant slide over each other, therefore alloys are a lot stronger than pure metals. An alloy is usually made by melting the main metal and then dissolving other substances into it.
Steel- Steel is our most important alloy. Most of the iron produced in the world is converted in to steel. Steel is an alloy since it is a mixture of iron with carbon and other metals. Steel is designed to have properties for specific uses. Low carbon steel- This steel contains less than 0.1% carbon. It is easily shaped and this makes it useful in mass production, eg car bodies. High carbon steel-This steel contains up to 1.5% carbon and is very hard. It can be used to make tools such as hammers. As more carbo is added to the steel, it becomes harder but less easy to shape.
Transition metals- These metals are found in the centre of the periodic table and come between group 2 and 3 eg iron, silver, nickle. Transition elements are typical elements and have all the physical properties of metals eg high melting points, high denisty Conductor of heat and electricity.
Recycling of metals- It takes less energy to melt, remould and recycle metals than it does to extract new metals from their ores. However, a lot of metals that we use are mixtures called alloys, and can be difficult to sort different metals for recycling.
Benefits- Amount of greenhouse gas emissions are reduced, less mining waste, uses less water, creates jobs and revenue.
Disadvantages-Expensive, time consuming, harmful, toxic chemicals, more energy and pollution.
Atoms- all substances are made up of atoms.
Elements- a substance that is made up of only one type of atom. Each element has its own chemical symbol They are shown on the periodic table. The columns on the table are known as groups and each group contains elements with similar properties. Most of the elements are metals. The…