ppt

1. Describing Matter
Matter is anything that has
mass and takes up space.
Chemistry is the study of
the properties of matter
and how matter changes.

2. Every form of matter has
two kinds of properties.
1. physical properties
2. chemical properties

3. Physical Properties
A physical property is a
characteristic of a pure
substance that can be
observed without changing it
into another substance.
The physical properties of
matter help you identify and
classify matter in its different
forms.

4. Examples of Physical Properties include
1.physical states of matter
2.density
3.Size
4.Luster
5.Smell
6.Texture
7.color
8.Flexibility
9.maleable

5. Examples of Physical
Properties continued
10. Ductile
11. Conducts heat and electricity
12. Dissolving
13. hardness

6. Chemical Properties
►A chemical property is a
characteristic of a pure
substance that describes
its ability to change into
different substances.

7. Examples of Chemical Properties
► 1. Rust forming on iron. Iron slowly
combines with oxygen in the air to form
a different substance called rust.
► 2. Ability to burn (make fire)
► 3. Ability to react with other
substances. (ex. Vinegar and baking
soda)
► 4. Yeast making bread dough rise.
Yeast being added to bread dough which
produces a gas that makes the bread
rise.
► 5. Ability to tarnish.

8. Elements
An element is a substance that cannot be
broken down into any other substances
by chemical or physical means.
In science, we list these elements on the
Periodic Table of Elements. There are
over 100 elements listed on this table
which can be found on pages 112-113
in your textbook.

9. Examples of Elements
Some examples of elements
include Oxygen, Hydrogen,
Nitrogen, Neon, Gold, Silver,
Zinc, Nickel, and Helium.
We will learn more about
elements later on during
marking period 2.

10. Molecules
It is 2 or more atoms held
together by chemical bond
►the atoms may be similar
like O2,N2
►OR different and this case
called compound like
NaCl,H2O

11. Compounds
A compound is a substance made
up of two or more elements
chemically combined in a set
ratio.
A compound is represented by a
chemical formula, which shows
the elements in the compound
and the ratio of the atoms.

12. Example of Compounds and
their Chemical Formulas
H2O represents water. This
ratio means 2 parts Hydrogen
and 1 part Oxygen.

13. More Examples of Chemical
Formulas
Carbon monoxide, a gas produced
in car engines, has the formula
CO; which means, 1 part Carbon
to 1 part Oxygen.
Carbon dioxide, a gas that we
exhale from our bodies, has the
formula CO2, which means 1
part Carbon to 2 parts Oxygen.

14. Mixtures
►A mixture is made up of
two or more substances –
elements, compounds, or
both – that are together in
the same place but are not
chemically combined.

15. Mixtures
►Each substance in a mixture
keeps its individual properties.
Also, the parts of a mixture are
not combined in a set ratio.
►Mixtures can be
►Heterogeneous or
►Homogeneous

16. Heterogeneous Mixtures
In a heterogeneous mixture you can see the
different parts.
Examples of heterogeneous mixtures include
1. A pizza with the works (pepper, onion,
sausage, pepperoni, extra cheese)
2. A fruit salad
3. Soil
4. A green salad

17. Homogeneous Mixtures
►The substances in a
homogeneous mixture
are so evenly mixed
that you can’t see the
different parts.

18. Homogeneous Mixtures
►Examples of homogeneous
mixtures include
1. Sweet Ice tea (tea and sugar)
2. Sugar water (sugar and water)
3. Solutions
4. Air (nitrogen, oxygen, other
gases)
5. Brass (copper and zinc)

19. Compounds vs. Mixtures
A compound can be difficult
to separate into its
elements. But, a mixture
is usually easy to separate
into it components because
each component keeps its
own properties.

20. Separating Mixtures
Some methods for separating mixtures
include
1. Using a magnet(for metals)
2. Filtering the mixture (allow water to
pass ans prevent the large molecules to
pass)
3. Distilling a liquid solution(separating 2
liquids by boiling them, the one with low
boiling point will evaporate first)
4. Evaporation (separate dissolved
substance from water as seasalt)

22. Knowledge Check
►What is the difference
between chemical and
physical properties?

23. Answer:
► Physical properties can be observed
without changing pure substances
into other substances. Chemical
properties can be observed only be
changing pure substances into other
substances.

24. Knowledge Check
►What is the difference between
a heterogeneous mixture and a
homogeneous mixture?

25. Answer:
►In a heterogeneous mixture you
can see the different parts. In
a homogeneous mixture, the
parts are evenly mixed
together so you can’t see
them.