Slides in this set
Elements, Compounds and
Elements are substances that are made up of only
one type of molecule
· Compounds are chemically bonded molecules that
form when 2 of more elements react together
· Isotopes are different atomic forms of the same
element, which have the same number of protons
but a different number of neutrons
Examples of Isotopes
12 6 protons 6 protons 14
6 electrons 6 electrons
6C 6 neutrons 8 neutrons 6 C…read more
The Periodic Table 0
3 4 5 67
transitio poor non nobl separates
n metal metal e
metals and non-metals
metals s s gases
· Elements in each group have the same number of electrons in their outer
shell. They all have similar properties which is why the periodic table
looks like it does.
· If an element is in group 1, it will have one electron in it's outer shell, in
group 2 they will have 2 etc.…read more
· Electrons always occupy outer shells
(sometimes called energy levels)
·The lowest shells are always filled first -
these are closest to the nucleus
·Only a certain number of electrons are allowed
in each shell
·Atoms want to have full outer-shells, they are
a lot less reactive like this (Noble Gases in
maximum of 16 electrons
·But most atoms do not have full outer shells
which means that they want to react
How to Work Out Electronic
· Look at the periodic table and work out how many protons it has ( this is
the smallest of the two numbers) an atom has the same number of protons
and electrons. So..... you know how many electrons it has.
· You also know how many electrons need to be on each shell. If we take
Nitrogen as an example:
· It has 7 protons, so 7 electrons. It's atomic structure must be 2,5.…read more
Ionic Bonding = transferring
In ionic bonding, atoms gain or lose electrons to a charged particle (an
ion) which are then strongly attracted to one another (because + and -
· All atoms on the left of the periodic table have only one or two electrons
in their outer shell. They want to get rid of them so that they can be an
ion. With a full outer shell.
· The atoms on the right they have 6 of 7 electrons in the outer shell and
they're nearly full. They want to gain 1 or 2 more so that they can be ions
with a charge.
· If an atom loses electrons, it becomes positively charged
· If an atom gains electrons, it becomes negatively charged…read more
Ionic Bond Properties
How does an ionic bond react?
· Ionic bonds always produce giant ionic
· The ions formed are closely packed together.
· There are very strong chemical bonds between
all the ions
· They have high melting and boiling points because of
their really strong intermolecular bonds.
· They dissolve in solutions that conduct electricity.
This is because when dissolved the ions separate and
are free to move in the solution so they can carry
· They conduct electricity when molten. This is because
the ions are also free to move.…read more