Download The Elements

Characteristics of Substances
Elements, compounds, mixtures
Atoms
Smallest piece
Elements
Red block
Blue block
Each type of Atom is called an Element
LEGO
Different colours ,sizes and
shapes
WORLD
Different properties
• Elements are substances made up of only one
type of atom.
• Example:
Molecules
A molecule is made up of two or
more atoms chemically combined.
O
H
H
Water (H2O)
Chemical Reaction
Element or Molecules combining together
= > Chemical Reaction
O
+
O
H
H
H
H
Water (H2O)
Aristotle's Elements
Earth
Air
Fire
Water
What is an Element ?
• Everything in the Universe is made from
Elements
• There are over 100 elements
• The most common element in the Universe is
Hydrogen
• The Term “Element” was introduced by an
Irish scientist Robert Boyle –
–
“Simple Substance”
Element
An Element is a substance that cannot be split up
into simpler substances by chemical means.
Common Elements
Oxygen – Most abundant Element
in Earths Crust
What is this ?
Element
Oxygen
Carbon
Hydrogen
Nitrogen
Calcium
Phosphorus
Potassium
Sulfur
Sodium
Magnesium
Copper, Zinc, Selenium, Molybdenum, Fluorine,
Chlorine, Iodine, Manganese, Cobalt, Iron
Percentage
65%
18%
10%
3%
1.5%
1.0%
0.35%
0.25%
0.15%
0.05%
0.70%
Lithium, Strontium, Aluminium, Silicon, Lead,
Vanadium, Arsenic, Bromine
Trace amounts
Periodic Table of Elements
Symbols
• Each Element is given a unique Symbol
– First letter of its name (H, C, O)
– First two letters of its name (Si, Ne, Li)
– Taken from its Latin name (Pb, Fe, Au)
Metals
METAL
Copper
Zinc
Aluminium
Iron
Silver
Gold
SYMBOL
Cu
Zn
Al
Fe
Ag
Au
Non Metals
NON METAL
Carbon
Oxygen
Sulphur
Hydrogen
Nitrogen
SYMBOL
C
O
S
H
N
Atom
An Atom is the smallest particle of an Element
that still retains the properties of that element.
What’s inside the atom?
Compounds
A Compound is a substance that is made up of
two ore more different elements combined
chemically together.
Compounds
H
O
C
H
H
H
H
Water (H2O)
H
Methane (CH4)
O
C
Carbon Dioxide (CO2)
O
Compound ?
O
O
Oxygen (O2)
H
H
Hydrogen (H2)
• When a compound is formed during a
chemical reaction its properties differ from
those of the elements from which it is made
Mixtures
• A mixture consists of two or more different
substances mingled together but not
chemically combined.
• Examples:
Sea – water and salt
Air – nitrogen, oxygen …
Soil – sand, clay, humus …
Mixture vs Compound
Mixture
The amounts of the substances
in the mixture can vary.
Compound
The elements in a compound are
always present in the same fixed
proportion.
A mixture contains two or more A compound is a single
substances
substance.
The properties of a mixture are
similar to those of the
substances in a mixture.
The properties of a compound
are different to those of the
elements which reacted to form
it.
There are practically no energy Heat is usually given out or
changes when a mixture is made taken in when a compound is
formed.
It is usually easy to separate the It is usually difficult to separate
components of a mixture.
the components of a compound.