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1. Physical properties of metals and non-metals
In the table below is a clear summery of the general physical properties of metals and non-metals. You
need to know these properties for your exam.
Physical Metals Non-metals
properties
Electrical Good conductor Poor conductor, act as an insulator
conductivity (copper wires) (graphite is an exception)
Heat conduction Good Poor, act as an insulator e.g. rubber
(Iron cooking pans)
Sound when hit Rings Often dull
(wind chimes and church bells)
Lustre Shiny Dull
(shininess) (silver and gold jewellery and (graphite in pencils)
coins)
Malleability Easily bent Brittle
(ability to be bent) (copper water pipes, aluminium (diamonds shatter when hit hard. Graphite
cooking foil) snaps in pencils)
State Most are solids Most are gases, some are solid
Density High Low
(lead plumb line, gold bars) (carbon fibre in fishing rods)
Magnetic Only three metals None
(attracted to a (nickel, cobalt and iron)
magnet)
Reactivity series of metals
This is a list of metals (and often the non-metals carbon and hydrogen) in order of their chemical
reactivity. The most reactive is at the top and the least is at the bottom.
Element Symbol
Potassium K Most reactive *Aluminium seems unreactive in water and acidic
Sodium Na solutions because it has a thin, tough layer of
aluminium oxide on its surface.
Calcium Ca
Magnesium Mg **Two non-metals are in this series. This helps you
*Aluminium Al to understand the making of metals by reduction
using carbon and how metals react with acids and
**Carbon C water.
Zinc Zn
Iron Fe
Lead Pb
**Hydrogen H
Copper Cu
Silver Ag
Gold Au Least
reactive
Metals reaction with oxygen
Metals react with the oxygen in air, forming oxides. This can often be made clearer by reacting the
metal with pure oxygen. Below are some word equations. There is a description with the first example.
magnesium + oxygen magnesium oxide
Here magnesium metal has reacted with the oxygen in the air and has been oxidised. This means that
oxygen has joined to the magnesium making a compound from the elements. The compound is called
magnesium oxide. In general, metal + oxygen metal oxide. Use this description to help you through
the equations below.
zinc + oxygen zinc oxide
copper + oxygen copper oxide
calcium + oxygen calcium oxide
There are a few metals that do not react with oxygen in the air. They include the very unreactive
metals gold, platinum and silver.
Metals reacting with water
Metals above hydrogen in the reactivity series will react with water. The metals below hydrogen - like
copper, silver and gold - do not react with water or steam.
Lithium, sodium, and potassium all react well (fast, vigorously) with cold water. These metals react and
dissolve, producing an alkaline solution. This is a metal hydroxide solution. This turns Universal
Indicator purple. While reacting, hydrogen (which is a flammable gas) is given off. You can hear it
being made by the fizzing noise.
lithium + water lithium hydroxide + hydrogen
potassium + water potassium hydroxide + hydrogen
sodium + water sodium hydroxide + hydrogen
Magnesium is less reactive than these three. Therefore it only reacts slowly with cold water. It will
react vigorously with steam. The products are slightly different as the oxide is formed.
Once the magnesium has become very hot it starts to react with the steam in a very exothermic
reaction. The magnesium, which was silver in colour, becomes pure white and a flammable gas -
hydrogen - is formed. This is set on fire.
Metals reacting with acids
Metals (above hydrogen in the reactivity series) react with dilute acids.
The reaction involves:
1. The metal dissolving
2. Fizzing as hydrogen gas is being formed.
3. The test tube gets warm because the reaction produces thermal energy - i.e. it is
exothermic.
The general word equation is:
acid + metal hydrogen gas + a salt
A salt is a compound made from an acid when a metal has replaced the hydrogen. The table
below gives you the names of the salts formed when using each acid.
Acid Name of salt (and an example)
Hydrochloric acid Chlorides
(e.g. Sodium chloride)
Nitric Acid Nitrates
(e.g. Calcium nitrate)
Sulphuric acid Sulphates
(e.g. Magnesium sulphate)
Examples
zinc + sulphuric acid zinc sulphate + hydrogen
nitric acid + magnesium magnesium nitrate + hydrogen
calcium + hydrochloric acid calcium chloride + hydrogen
The chemical test for hydrogen gas
Take a lighted splint or spill and place it in the gas. If there is a squeaky pop - and often the splint or
spill is blown out - then the gas is hydrogen.
magnesium + water (steam) magnesium oxide + hydrogen
Displacement reactions
A displacement reaction happens between a reactive metal and a solution of a less reactive metal
compound. The more reactive metal will displace the less reactive metal from its compound in
solution.
What do you often observe (see, hear, feel) in this type of reaction?
1. The more reactive metal will dissolve.
2. The less reactive metal will appear at the bottom of the tube or plate on the more reactive
metal.
3. The solution may change colour.
4. The reactions are exothermic, so the tube gets warm.
Examples of displacement reactions
copper sulphate solution + magnesium magnesium sulphate solution + copper
iron + copper sulphate solution iron sulphate solution + copper
Obtaining a reactivity series from displacement reactions
The following metals are placed in the solutions shown. If a reaction takes place then an X is placed in
the box.
From the results you can tell which metal displaces another metal from its compound in solution.
Therefore the metal doing the displacing is more reactive.
Copper Silver Magnesium Zinc Lead
Copper nitrate
X X X
solution
Silver nitrate
X X X X
solution
Magnesium
nitrate solution
Zinc nitrate
X
solution
Lead nitrate
X X
solution
From the results above you can work out the reactivity series, follow the working out below.
Most reactive metal is Magnesium(4 ticks)
Zinc (3 ticks)
Lead (2 ticks)
Copper(1 tick)
Least reactive metal is Silver (0 ticks)
NAME OF NON- COMPOUND MADE ADD NON-METAL OXIDE TO FORMULA OF
METAL WHEN BURNT IN WATER – NAME OF ACID ACID
OXYGEN FORMED
Sulphur Sulphur dioxide Sulphuric acid H2SO4
Nitrogen Nitrogen dioxide Nitric acid HNO3
Wise up words
1. Physical properties (melting and boiling point, density, state)
2. Chemical properties (the substances chemical reactivity, the reactions it undergoes)
3. Displacement (One metal pushes another metal from its compound into solution)
4. Reactivity series (a list of metals in order of their chemical reactivity)
5. Salt (a compound formed from an acid where the hydrogen has been replaced by a metal
Non typical metals and non-metal elements
Mercury is a metal and it is a liquid at room temperature. The bonding
between the atoms of mercury is not as strong as in most metals. It is
therefore a liquid at room temperature as there is enough thermal energy to
allow the bonds to be broken. This gives the mercury atoms enough kinetic
energy to allow them to move position.
Diamond is a form of carbon and is a non-metal element.
Most non-metals are gases or low melting point solids, but diamond is a
high melting point solid. It is also a very hard substance. These properties
are due to the extensive and strong bonding between the carbon atoms in
diamond.
The bonds are arranged in three dimensions between the carbon atoms. These bonds are strong.
Graphite is another form of carbon (another allotrope of carbon). It is a non-typical, non-metal element,
because it conducts electricity. The layers of carbon atoms have free mobile electrons between them.
These allow graphite to conduct electricity.
Metals reacting with oxygen
Metals will react with oxygen in air or pure oxygen to form oxides. The metals are oxidised. The
reactions below show this process. Two elements are reacting together to form a single new
compound which is an oxide.
Here the magnesium atoms are reacting with oxygen molecules (an oxidation reaction) to make the
compound magnesium oxide.
2Mg + O2 2MgO
Likewise copper atoms are bonding or joining to oxygen atoms from the oxygen molecule in this
oxidation reaction. The new substance formed is the compound copper oxide.
O2 + 2Cu 2CuO
In general:
metal + oxygen metal oxide
Some notable exceptions are silver and gold, which do not react with oxygen.
Metals reacting with water
Lithium, sodium, and potassium all react (fast and vigorously) with cold water. These metals react and
dissolve, producing an alkaline solution of pH 11 to 13. During this reaction hydrogen, a flammable
gas, is given off. You can hear it being produced by the fizzing noise.
In the first example below, you would see a silvery piece of potassium metal floating on the water. It
would be on fire, as the hydrogen gas produced will burn with a purple flame. Soon, the metal will
have all reacted and dissolved, making the water alkaline and all the fizzing will have ceased.
potassium + water hydrogen + potassium hydroxide
2K + 2H2O H2 + 2KOH
Magnesium is less reactive than the above three. It only reacts slowly with cold water. It will, however,
react vigorously with steam. The products are slightly different as the oxide is formed.
Mg + H2O(g) MgO + H2
Metals reacting with acids
All acids are compounds of hydrogen. It is this hydrogen that is displaced by the metal when it reacts
with an acid. Only metals above hydrogen in the reactivity series can cause this displacement, so only
metals above hydrogen in the reactivity series react with dilute acids. Therefore you always get
hydrogen gas as a product in this type of reaction. The metal dissolves and forms a salt as the other
product in the reaction.
The general word equation is:
acid + metal hydrogen gas + salt
The reaction involves the following observations:
1. The metal dissolving
2. Fizzing as hydrogen gas is formed.
3. The test tube gets hot as an exothermic reaction is taking place.
4. After the reaction has finished the solution becomes clear.
Examples:
zinc + sulphuric acid zinc sulphate + hydrogen
Zn + H2SO4 ZnSO4 + H2
sulphuric acid + magnesium hydrogen + magnesium sulphate
H2SO4 + Mg H2 + MgSO4
Special Note: the chemical test for hydrogen gas. Take a lighted splint or spill and place it in the gas.
If there is a squeaky pop, then the gas was hydrogen.
Metals, acids and reactivity
To work out the order of reactivity of these four metals (Ca, Cu, Zn & Mg) place pieces of each metal
into dilute hydrochloric acid. Now look at the tubes. Which tube (metal) is reacting the most quickly?
Now which one is not reacting? Put the other two tubes (metals) in the correct order. Now make a
reactivity series list. Most reactive metal at the top.
From the observations above it is clear that the order of reactivity is
Ca Most reactive metal
Mg
Zn
Cu Least reactive metal
Salts
This word has come up many times and it always confuses people. A salt is a compound made when
a metal replaces the hydrogen in an acid. There are many salts that you use.
1. Common salt (sodium chloride)on your chips
2. Bath salts (sodium carbonate)
3. Low salt (potassium chloride) as a healthier alternative to common salt in cooking
4. Epsom salts (magnesium sulphate) for indegestion
The table below will help you understand the definition of a salt.
Naming salts
See how the name of the salt comes from the acid used.
Name of acid Formula of Name of the salt made by An example Formula of the
acid the acid example
Hydrochloric HCl Chlorides Sodium chloride NaCl
acid
Sulphuric acid H2SO4 Sulphates Magnesium MgSO4
sulphate
Nitric acid HNO3 Nitrates Potassium nitrate KNO3
4. Chemical properties of non-metals
Non-metals react with oxygen and form oxides. There is a little description to guide you through each
one
Here sulphur powder is heated on a combustion spoon until it is on fire (blue flame). Then it is placed
in a gas jar of oxygen. The sulphur bonds with the oxygen making the compound sulphur dioxide.
S + O2 SO2
During lightning the high temperature cause the nitrogen and oxygen gases in the air to react and
combine. The nitrogen and oxygen molecules are given loads of energy by the lightning. They zoom
around and smash into each other and join. One nitrogen atom joins with two oxygen atoms to make
the compound nitrogen dioxide.
N2 + 2O2 2NO2
These non-metal oxides, sulphur dioxide and nitrogen dioxide, dissolve in water and form acidic
solutions. Acids are made when water reacts with non-metal oxides. The table below summaries this
for you.
Making acidic solutions from non metal elements
This table shows how you can change a non-metal element into an acid solution. It also shows you the
connection between the name of an acid and the non-metal element from which it was formed.
Non-metal Name of compound formed Formula Name of acid formed by Formula of
element through reaction with oxygen dissolving this oxide in acid
water
Sulphur Sulphur dioxide SO2 Sulphuric acid H2SO4
Nitrogen Nitrogen dioxide NO2 Nitric acid HNO3
