Elements & Atoms
An element is made up of same type of atoms which are chemical bonded; everything on earth is made up of atoms. Elements cannot be split into anything simpler by any chemical methods because an element only contains one type of atom.
Periodic table
There are about 100 different type’s elements on the periodic table, each element on the periodic table has their own symbol. The first letter of the elements symbol has to be start with a capital letter on the periodic table. Elements on the periodic table are specially arranged so that every column contains elements with very similar properties. These columns are called groups. The rows on the periodic table are called periods. There’s always a gradual change or ‘tend’ in properties across a period. Elements on the left side of the periodic table are magnetic elements and the elements on the right side of the periodic table are non-magnetic elements.
Elements
Symbols
Magnesium
Mg
Iron
Fe
Zinc
Zn
Nickel
Ni
Oxygen
O
Carbon
C
Helium
He
Compounds
Compounds contain two or more different types of elements which are chemical bonded. It is not easy to spilt compounds to a simpler form. In addition to this, compounds cannot be found on the periodic table because they aren’t elements. The particles in a compound are called molecules- formed when atoms bond.
Examples of molecules in a compound:
Word equations
Compounds has equation to show the chemical reactions of elements combining together to make a compound.
Examples of word equations:
Iron+Sulphur iron sulphide
Carbon+oxygen carbon dioxide
Copper+chlorine copper chloride
Magnesium+oxygen magnesium oxide
In symbols:
Chemical reactions
In chemical reactions there are 2 or more chemical (called reactants) combining them together to form one or more new substances (called products). The new compound produced by any chemical reaction is always different from the original element (or reactants). A new compound is sometime called synthesised an example of this is iron reacting to sulphur.
Iron sulphide:
Iron is a magnetic element and sulphur is a completely different element from iron it is non-magnetic. When these two elements mixes together is make a mixture of iron and sulphur it will be easy to separate these two elements by just using a magnet because iron is magnetic so when you put the magnet next to the mixture the iron will attract to the magnet and the mixture will be separated. However when the mixture of iron and sulphur gets heated up together the iron will react with the sulphur and it will form iron sulphide the compound won’t be magnetic so then you cannot separate the iron for sulphur so this compound will be called synthesis.
Molecules of some compounds:
Mixtures
Mixtures are made up of different substances but they aren’t chemically bonded. For example powered iron and powered sulphur mixed together makes mixture of iron and sulphur. They can be separated from each without a chemical reaction, in the way that different coloured sweets can be picked out from a mixed packet and put in separate piles. From meaning of this mixtures be separated easily without any chemical methods but you can use the physical methods to separate very easily.
There are 4 separate techniques of physical methods and they are:
Filtration
Evaporation
Chromatography
Distillation
Filtration & evaporation (separation of rock salt)
Rock salt is basically a mixture of salt and sand. Salt and sand are both compounds- however salt dissolves in water and sand doesn’t.
The 4 steps of the method to separate rock salt:
1. Grinding : grind up the rock salt with a pestle and mortar
2. Dissolving: dissolve in beaker and stir
3. Filtering: filter through filter paper in a funnel.
4. Evaporation: evaporate in an
