The periodic table is a collection of over
100 elements organized into groups and periods.
In this video I will be covering the 5 major
groups of the periodic table. The Alkali Metals,
the Alkaline Earth Metals, The Halogens, the
Noble gases, and the transition metals.
Starting with the Alkali Metals.
The alkali metals have one electron in their
outer shell meaning they need to lose one
electron in order to have a full shell. There
are a few trends down the group you might
need to know.
Those are the density which increases as you
go down the group, the Softness which increases
down the group, the Melting and Boiling points
which increases down the group and the Reactivity
which increases down the group.
Physical properties of Alkali Metals include:
Good conductors of heat and electricity, light
and not very dense, and low melting and boiling
points compared to other metals.
Alkaline earth metals are essentially the
same but their features are less exaggerated.
The one major difference is that Group 2 elements
have 2 electrons in their outer shell.
Halogens are the 7 or 17th group of the periodic
table, depending on the one you're looking
at.
They have 7 electrons in their outer shell
meaning they need to gain one electron and
become a negative ion in order to be stable.
Trends down the group are:
The density increases down the group, the
colour deepens, the melting points increase
and this is the important one, REACTIVITY
DECREASES.
Using your knowledge on the reactivity of
Halogens you have to be able to explain their
displacement reactions with a halide. Both
Bromine and Iodine can't displace Chlorine
because chlorine is more reactive. Chlorine
can displace Bromine because of the same principle.
Apply the same logic to the rest and you'll
be left with something like this.
Next, are the noble gases, from group 8, 18,
or 0.
They have a full outer shell of electrons.
They also have trends down the group. The
Density, Size and mass of the atoms, and the
Melting points all increase. However, noble
gases have a special property regarding their
reactivity...
They are UNREACTIVE. This is due to their
full electron shell. Because the shell is
full they don't need to react with anything
to become stable.
Finally transition metals. Transition metals
are located in the centre area of the periodic
table and have no trends that you need to
learn. Nevertheless, they still have many
physical and chemical properties.
Their physical properties include being high
density, hard, strong, and having a high melting
point.
Chemical properties include being much less
reactive than group 1 and 2 metals, many form
coloured compounds unlike group 1 metals which
form white compounds, and transition metals
have variable valencies, meaning it can lose
more electrons than just the ones in it's
outer shell.
Thanks for watching; I hope you found it useful
and be sure to watch some of my others videos
here.
