All elements
can be found
inside the
periodic
table.
An element is a substance
that cannot be brokn down.
Compounds are a
substance that
contains 2 or
more different
types of atoms.
Magnesium + Chlorine
---> Magnesium Chloride
...ate means oxygen is
involved in the reaction
Electricity can
break
compounds
apart
MgO(2) is a formulae
Mg is in group 2
Oxygen is diatomic - O(2)
It is in group 6
This adds up to 8 and it has a
full outer shell. It is Happy :)
If 2 or more elements join be sharing
electrons , it is a molecule
Mixtures are more than one type of atom not
chemically joined. This means they can easily
be separated from eachother
Filtration - This technique separates a insoluble
liquid from a solid. One beaker contains solid and
liquid , the other is filter paper.The mixtueres are
both poure din and the solid will be left behind, the
solid will not.
Crystallisation can be used to
separate a solid dissolved in
liquid.
Distillation is separating out liquids with different boiling points
Chromatograpghy is separating out the different
coloured inks.
Theories of the atom
1. 400 BC, Democritus suggested the
atom was a group of small
particles that could not be
divided.
2. John Dalton, 200years after suggested the
atom was a "billiard ball" that could not be
divided
3.1897 ,JJ. Thompson discovered the
electron and said the electrons were
embedded in a ball of positive
charge, like a Plum Pudding.
4. 1909 Geiger and Marsden found interesting results and with Ernest Rutherford, they discovered
that the atom had a nucleus and Rutherford said that it has a positive charge in the
centre where the mass is concentrated and much was empty space . This is the nuclear model
5. 1913, Niels bohr used
Elecron has a negative charge,
Proton has a positive charge and
Neutron hasn't got a charge.
Relative Atomic mass mass can be found by : (Mass of first
Isotope x %of first Isotope) x (mass of 2nd Isotope x % of second
Isotope)