Download exploring the nature of matter

SNC1D1 NOTES: EPLORING THE NATURE OF MATTER
Matter: the stuff from which our physical world is formed. It is commonly defined as
being anything that has mass and that takes up space (has volume). Matter does not
include any form of energy such as light, heat and sound.
On a first analysis, the possible phases are:
 gaseous, such as air
 liquid, such as water
 solid, such as rock
However, for classification purposes it is useful to divide materials into:
a) mixtures:
b) pure substances:
Definitions
1. Atom: The simplest unit of an element that cannot be broken down any further
and still remain an element. An Atom is made up of smaller subatomic
particles: proton, neutron and electron
Master Yoda
Much Learning You Have Yes!
2. Element: A pure substance that cannot be broken down into other simpler
substances. It is composed of atoms of only one type. (eg, oxygen is only
composed of oxygen atoms, and silver is only composed of silver atoms.
Silver Surfer
3.
Master Yoda
Gold Coin
Compound: A pure substance that is composed of two or more different
elements bonded together by ionic bonds. The properties of a compound are very
different from the properties of the elements of which it is composed.
Much Learning You Have Yes!
4.
Molecule: The smallest particle of a pure substance possessing two or more
non-metallic elements bonded together by covalent bonds. These atoms can be
the same are different.
DIFFERENT EXAMPLES OF MOLECULES
\\
5. Pure Substance: Is composed of only one substance, basic unit or particle.
Example, hydrogen, oxygen, water, carbon dioxide, etc
Master Yoda
Much Learning You Have Yes!
Master Yoda
Much Learning You Have Yes!
SNC1D1 NOTES: PHYSICAL VS CHEMICAL CHANGE
PHYSICAL CHANGE
In a physical change, the substance involved remains the same, even though it
may change state or form. Changes of state, dissolving are examples of
physical changes.
CHEMICAL CHANGE
In a chemical change the original substance is changed into a different
substance that has different properties. Burning, cooking, and rusting are all
examples of chemical changes.
Master Yoda
Much Learning You Have Yes!
CLASSIFICATION OF SUBSTANCES
Matter can be classified into two categories: Pure Substances and
Mixtures
A - Recall that a pure substance is composed
of one kind of
particle or substance only. For example
pieces of
aluminum foil contains only aluminum
particles and water
only contains one type of molecule.
B - A mixtures is composed of two or more
pure
substances each of which have
different properties.
A mixtures composition is not
uniformed –
i.e. we can change the composition
of a mixture.
 All samples of the same pure
substance have the
same properties and composition
Example:
Salt and Pepper is a mixture - we
may add a
little bit of salt
we may mixed
add a lot
of
We
cannot changeMixtures
the composition
of a in which the compounds
C - Homogeneous
are mixtures
areoruniformly
together
salt
pure and the separate
to makehave
a mixture
of
substance
components are not visible. Samples from different with
partsthe
of pepper
such a mixture
the same
salt
composition while the
substance in the mixture retain their own properties.and pepper
D - Heterogeneous Mixtures consist of two or more phases or regions of matter where the
components are visible
that. Each phase can be distinguished from surrounding regions by its properties. ie. salt and
pepper : white salt and
black pepper, pizza, checkered T-shirt
Master Yoda
Much Learning You Have Yes!
 Solutions are homogeneous mixtures made up of one or more substances
dissolved in another
substance.

A solution may be liquid, solid or gas. For example the gold used to make
jewellery is
actually a solution of metals, gold and copper.

True solutions are clear and appear to be the same (homogeneous)
throughout the sample

Solutions are composed of solute and solvent. The solute is the
substance being
dissolved and the solvent is the substance doing the dissolving. For
example: sugar water
solution, the sugar would be the solute and the water would be the
solvent.
SUBSTANCE CAN BE CLASSIFIED AS A MIXTURE IF IT MEETS THE FOLLOWING
CRITERIA
a) Its composition is variable - in other words, two or more substance can be
mixed together in almost any proportion. For example you might like a lot of milk
with your cereal or you may like a little bit of milk with your cereal.
b) Its component (parts) can be separated by physical means - Salt can be
obtained from fresh seawater by boiling off the water. Some examples of common
mechanical (physical) methods of separating mixtures are…
i)
sifting or sieving the mixture through a screen
ii)
removing metal particles with a magnet
iii)
filtering (eg sand and water)
iv)
distilling - vaporizing (boiling) a liquid in a mixture, and then recovering it
by condensation
c) Change of state occurs over a range of temperatures:
When a mixture undergoes a change of state, the observed temperature is not
constant. Example:
A mixture of alcohol and water boils between 80oC and 100oC, however on its
own, ethanol alcohol
boils at 79oC and water boils at 100oC.
Master Yoda
Much Learning You Have Yes!
HOW TO TELL COMPOUNDS AND MIXTURES APART
Listen Young Ones, you may sometimes find it difficult to decide whether a substance
is a compound or mixture. With the aid of the force and these four clues, your journey
will be much easier.
CHARACTERISTICS OF COMPOUNDS AND MIXTURES
COMPOUND
i) properties of the compound are
different
from the properties of the
components. Salt
is made up of sodium (Na) and
chlorine (Cl)
- individually sodium is a shinny
metal, chlorine
is a yellow poisonous gas,
combine together
they make salt
ii) Components are present in fixed
proportions
eg, H2O is composed of two
hydrogen and
one oxygen, we cannot add or
subtract the
Master Yodanumber of atoms and still be water
- H2O2 is peroxide - lethal if
swallowed
MIXTURES
i) Components retain their own
properties.
eg. salt & pepper mixture, the salty
is a still salty,
white, and solid, & the pepper is still
black, hot,
and a solid
ii) Components are present in varying
proportions
eg. salt and pepper mixture - we
can vary the
amount salt or water added
iii) Can be created and separated by
physical
means
iv) Creation and separation does not
Much Learning You Have Yes!
involve
chemical means
Master Yoda
Much Learning You Have Yes!