Cambridge IGCSE Chemistry Properties, Uses & Alloys of Metals PDF

Head to www.savemyexams.com for more awesome resources Cambridge (CIE) IGCSE Your notes Chemistry Properties, Uses & Alloys of Metals Contents Properties of Metals Uses of Metals Alloys...

Head to www.savemyexams.com for more awesome resources Cambridge (CIE) IGCSE Your notes Chemistry Properties, Uses & Alloys of Metals Contents Properties of Metals Uses of Metals Alloys Page 1 of 9 © 2015-2025 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers  Head to www.savemyexams.com for more awesome resources Properties of Metals Your notes Physical properties of metals & non-metals The Periodic Table contains over 100 different elements They can be divided into two broad types: Metals Non-metals Most of the elements are metals and a small number of elements display properties of both types These elements are called metalloids or semimetals Page 2 of 9 © 2015-2025 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers  Head to www.savemyexams.com for more awesome resources The metallic character diminishes moving left to right across the Periodic Table Properties of metals Your notes Conduct heat and electricity This is because metals have delocalised electrons that are able to move through the metal structure Are malleable (can be hammered and made into different shapes) and ductile (can be drawn into wires) This is because the layers of positive metal ions, in the metal structure, are able to slide over each other Usually have high melting and boiling points This is because there is a strong electrostatic attraction between the positive metal ions and delocalised electrons (metallic bondmetallic bond) This strong attraction / bond requires lots of energy to break Properties of non-metals Do not conduct heat and electricity This is because all of the electrons are involved in covalent bonding One exception to this is graphite Are brittle when solid and easily break up They are not malleable or ductile One exception to this is graphite Low melting and boiling points Many non-metals are gases at room temperature This is because they have weak forces between molecules These weak intermolecular forces do not require a lot of energy to overcome Exceptions to this include diamond and silicon(IV) dioxide Chemical properties of metals The chemistry of metals is studied by analysing their reactions with water, dilute acid and oxygen Based on these reactions, a reactivity series of metals can be produced Page 3 of 9 © 2015-2025 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers  Head to www.savemyexams.com for more awesome resources Reactions of metals with water Some metals react with water, either warm or cold, or with steam Your notes Metals that react with cold water form a metal hydroxide and hydrogen gas metal + water → metal hydroxide + hydrogen For example, calcium: Ca (s) + 2H2O (l) → Ca(OH)2 (aq) + H2 (g) Metals that react with steam form a metal oxide and hydrogen gas metal + water → metal oxide + hydrogen For example, zinc: Zn (s) + H2O (g) → ZnO (s) + H2 (g) Reactions of metals with acids Most metals react with acids, such as HCl When acids and metals react, the hydrogen atom in the acid is replaced by the metal atom to produce a salt and hydrogen gas metal + acid → salt + hydrogen For example, iron: Fe (s) + 2HCl (aq) → FeCl2 (aq) + H2 (g) Reactions of metals with oxygen Unreactive metals, such as gold and platinum, do not react with oxygen Some reactive metals, such as the alkali metals, react easily with oxygen Copper and iron can also react with oxygen, although much more slowly When metals react with oxygen a metal oxide is formed metal + oxygen → metal oxide For example, copper: 2Cu (s) + O2 (g) → 2CuO (s) Page 4 of 9 © 2015-2025 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers  Head to www.savemyexams.com for more awesome resources Uses of Metals Your notes Uses of metals What is aluminium used for? Aluminium sits above hydrogen in the reactivity series, which means that is a reactive metal Aluminium quickly reacts with oxygen to form a protective layer of aluminium oxide, which is why aluminium appears to be unreactive Uses of aluminium Use Property aeroplane bodies high strength-to-weight ratio, low density overhead power cables good electrical conductor, low density saucepans good thermal conductor food cans non-toxic, resistant to corrosion and acidic food stuffs What is copper used for? Copper sits below hydrogen in the reactivity series, which means it is an unreactive metal The uses of copper relate to its properties For example, it is an excellent electrical conductor and ductile so is used in wiring Page 5 of 9 © 2015-2025 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers  Head to www.savemyexams.com for more awesome resources Your notes Copper is usually the metal inside electrical wires due to it's high conductivity Uses of copper Use Property electrical wiring very good conductor of electricity and ductile pots and pans very good conductor of heat, unreactive, malleable water pipes non-toxic, unreactive (does not react with water) and malleable surface in hospitals antibacterial properties Page 6 of 9 © 2015-2025 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers  Head to www.savemyexams.com for more awesome resources Alloys Your notes Properties & uses of alloys An alloy is a mixture of a metal with other elements Most alloys contain more than one metal Some alloys contain non-metals Properties and uses of alloys Two examples of alloys are: Brass - an alloy of copper and zinc and is much stronger than either metal It is used in musical instruments, ornaments and door knobs Stainless steel - an alloy of iron and other elements, for example, chromium, nickel and carbon It is used in cutlery because of its hardness and resistance to corrosion / rusting Other alloys include: Iron with tungsten - extremely hard and resistant to high temperatures Iron with chromium / nickel - resistant to corrosion Aluminium with copper, manganese and silicon - the alloy is stronger but still has a low density, which makes it ideal for aircraft body production Alloys often have properties that are different to the metals they contain For example, they can be: Stronger Harder Resistant to corrosion / extreme temperatures These enhanced properties can make alloys more useful than pure metals The structure of an alloy Alloys have a different structure to metals Metals have a regular arrangement of ions Alloys have an irregular arrangement of atoms Page 7 of 9 © 2015-2025 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers  Head to www.savemyexams.com for more awesome resources Your notes The regular arrangement of a metal lattice structure is distorted in alloys Examiner Tips and Tricks Alloys are mixtures of substances. They are not chemically combined, which means that alloys are not compounds. Questions on this topic often give you a selection of particle diagrams and ask you to choose the one which represents an alloy. It will be the diagram with uneven-sized particles and distorted layers or rows of particles. Explaining the properties of alloys Extended tier only Alloys typically contain atoms of different sizes This distorts the normally regular arrangements of atoms in metals The regular arrangement in a metal is layers of positive ions in a sea of delocalised electrons Page 8 of 9 © 2015-2025 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers  Head to www.savemyexams.com for more awesome resources The distortion makes it more difficult for the layers to slide over each other So, alloys are usually harder / stronger than pure metals Your notes Page 9 of 9 © 2015-2025 Save My Exams, Ltd. · Revision Notes, Topic Questions, Past Papers