Metals and Non-metals 70,71
Most elements are metals . All of the non-metals are in the top right hand corner of the periodic table.
These are the properties of metals:
- They conduct electricity
- All metals are solid at room temperature (apart from mercury)
- Metals are shiny
- Metals are good at conducting heat
- Metals are usually hard
Non-metals do not conduct electricity.
All non-metals burn in oxygen (combustion) to make an acidic oxide. 68
Eg. Sulphur + Oxygen Sulphur Dioxide
S + O2 SO2
All metal elements burn in oxygen to make basic (alkaline ) oxides.
Eg Sodium + Oxygen Sodium oxide
4 Na + O2 2 Na2O
Groups and Periods 56
A horizontal line going across the periodic table is called a period of elements. The top layer is called the first period . The second row is called the second period etc.
A vertical line going down the periodic table is called a group of elements . The first column is called Group 1 . Elements in the same group have similar properties.
There are eight groups of elements on the periodic table .(Groups 1,2,3,4,5,6,7,0)
The number of the group that an element is in tells you the number of electrons that are in the outside shell of an atom of that element.
Eg group 7 elements have 7 electrons in the outside shell of their atoms. 8
Group 1 59,60
The first group are called Group 1 or the alkali metals. The main elements are Li, Na, K .
They are all very reactive . They must be stored under oil to stop them reacting with oxygen in the air. They have a dull outside layer which is made of oxide. They are soft and can be cut to reveal a shiny metal which quickly reacts with oxygen in the air.
All of the group 1 elements react strongly with water to make hydrogen gas and an alkali solution of a hydroxide.
Eg Sodium + Water Hydrogen + Sodium Hydroxide
All of the group 1 metals make compounds by reacting with non-metals . The compounds can be identified by doing a flame test and burning them .
Sodium compounds make orange flames. Lithium compounds make red compounds. Potassium compounds make lilac coloured flames.
All the compounds of alkali metals are soluble (they dissolve in water to make colourless solutions)
The lower a group 1 metal is down the group the stronger it is at reacting. (K>Na>Li)
Group 7 62,63
The group 7 elements are called the halogens. The main elements in group 7 are Fluorine , Chlorine , Bromine and Iodine.
All of the group 7 elements are reactive non-metals . Fluorine is the strongest reacting halogen. The lower a halogen is down the group the less reactive it is.
Chlorine is used as an antiseptic (killing germs in swimming baths)
Iodine solution is used as an antiseptic.
Solutions of the halogens can be identified by adding silver nitrate solution to them.
If a halogen is present then a solid precipitate is formed.
Silver bromide is used in photography because it changes colour when light hits it (it is photosensitive)
Hydrochloric acid can be used to etch the surface of metals.
Group 1 elements react with group 7 elements to form compounds . They react together by transfering electrons from the group 1 atoms to the group 7 atoms.
Group 0 58
Group 0 are called the noble gases . The lower down the group they are the heavier, more dense they are.
The noble gases will not react with other elements because they have a full outside shell of electrons which is very stable.
Group 0 gases can be used in coloured lighting .
Transition Metals 76
Transition metals do not fit into any group but they have these properties in common:
- They are hard and shiny
- They have high melting points
- They are strong and dense.
- They react with non-metals to make compounds which dissolve in water to make brightly coloured solutions. (eg Copper makes blue compounds, Iron makes orange or green compounds)
Transition metal carbonates break down and make carbon dioxide gas when heated. They change colour in the process.
Eg Copper carbonate heating Copper oxide + Carbon Dioxide gas
(green powder) (black powder)
Copper can be used to make water pipes.
Iron is used as a catalyst.
Solutions of transition metal ions can be identified by adding a solution of sodium hydroxide .
A coloured precipitate (solid) is made.
Ions , Atoms and Molecules
Any symbol that has an electrical charge on is an ion ( eg Cu2+ , Fe3+ , Cl- , O2- , I- )
Any symbo
