Transcript snc2l u2l7 the atom and the periodic table

The Periodic Table and the
Atom
Lesson 7
Elements

Elements are
pure
substances that
consist of atoms. The periodic table consists
of over 100 elements all of which have a
certain spot on the table.
Elements
MetalsLeft
side of the periodic
table
 The majority of elements on the periodic
table are
metals . All metals, except
for mercury are
solids
at room
temperature.

Metals
Metals have the following properties.

Malleable
: The ability to be
hammered or bent into a shape.

Lustre
: They are shiny in
appearance.

Ductile
: They can be pulled
into a wire.

Conductor
of electricity:
Electricity can travel through the metal
Non-metals
Non-MetalsRight
side of the
periodic table
 Most of the remaining elements in the
periodic table are
non-metals

.
Non-metals
Non-metals generally have these properties:

Non-conductor
of
electricity in its solid form
 At room temperature most are
gasses
or
solids
.
 Solids are
brittle
and lack the
lustre of metals

Metalloids
Metalloidsmiddle
right of the
periodic table
 Some elements do not fit as metals or nonmetals. These fit on either side of the
staircase that divides the metals and the
non-metals. They have some properties of
metals and some properties of non-metals.

Group Names
Alkali Metals: This is the
first
group in
the periodic table. They are
soft
,
silver coloured,
solids
and at
room temperature and react violently with
water. They must be stored in oil to prevent
them from reacting.
Alkaline Earth Metals
Alkaline earth metals: This is the
second
group in the periodic table.
They are light, very reactive,
solids
at room temperature and all react with
oxygen in the air.
 conduct
electricity

Transition metals

Transition metals: Theses metals have a
wide variety of properties and relativities.
They are generally
hard
,
strong metals that conduct electricity
Representative elements

Representative elements: Groups 1,2 and
13-17. There are
metals
and
non-metals. Some are solids while others
are gases and there is one
liquid
.
They follow the periodic law.
Halogens

Halogens: Non-metals in group 17. They
may be solids, liquids or gasses and are
extremely
reactive
.
Noble Gasses

Noble gasses: They are
gasses
at room temperature. They have a low
melting point and boiling point. They are
also very
un-reactive
.
Elements and Atomic
Structure
Atoms are composed of three subatomic
particles
1. Protons- Heavy positively charged found in
the nucleus
2.
Neutrons -are neutral particles that have
the same mass as protons and are located
in the nucleus
3.
Electrons- Negatively charged particles
with almost no mass. They circle the
nucleus at different energy levels.


Atoms are electronically neutral so the
number of electrons = the number of protons
Bohr Diagrams

To represent electron arrangements at
various orbits we use Bohr diagrams. Each
orbit has a set number of electrons.
Orbit #
# of Electrons
1
2
2
8
3
8
4
18
Ions- if an electron loses or gains an
electron it is called a ion.
 If it loses an electron it has a Positive ion
charge because there are more protons
than electrons.
 If it Gains an electron it has a Negative ion
charge because there are more electrons
than protons.

Practice

Lets Draw some H, He, Li, S, Ca