This document discusses the properties of matter and materials. It defines key terms like element, molecule, and compound. Elements are substances made of only one type of atom, while compounds are made of different types of atoms bonded together. The document classifies all elements as either metals or non-metals and describes some common properties of each, such as conductivity and density. It provides examples of uses for some non-metals like chlorine, phosphorus, and iodine. The document also discusses metal alloys and some materials' properties including flexibility, hardness, transparency, and heat/electrical conductivity.

1. Properties of matter
and materials
Chemistry
Chapter 9

2. Is water an element?
• People believed that water was an element until about 1800.It was only then
that a scientist passed electricity through water and found that it split up into
two gases (Hydrogen and oxygen).

3. Review
• Atom : The smallest building unit of matter.
• Element : A substance that is made of just one kind of atom.
• Molecule : A small group of same type of atoms joining together tightly.
• Compound : Group of different atoms joined together tightly.

4. Elements
A substance that has only one kind of
atom.
93 elements are natural, while 24 are man
made.

5. Particle accelerator
• Is an apparatus used to make atoms of new elements by adding particles inside
the accelerator and then made to crash into each other.

6. Metals
and non-
metals
- Scientists divided all the elements into 2
groups:
Metals and non-metals

7. Look at the following pictures and
describe some of their properties
Metal Non-metal

8. Property Metal Non-metal
Surface Shiny Dull
Physical state at room
temp.
Usually solid Solid, liquid or gas
Strength Shaped by pressing and
stretching without
breaking easily
Soft or brittle
Melting point Usually high Usually low
Boiling point Usually high Usually low
Density Usually high Usually low
Conduction of heat Good Very poor
Conduction of electricity Good Very poor

11. Non-metal Use
Chlorine - Purify water (kills microorganisms)
- In swimming pools (keeps the water
clean)
Phosphorus - Used on tip of matches
Iodine - Used in some portable water purifying
kits (used by people who take adventure
holidays)

12. - Some metals and non-metals are exception to the rules.
Example:
- Magnesium (metal), but it has a dull surface when heated it
catch fire and burns with a brilliant white flame.
- Graphite (non-metal), is form of carbon and used to make
pencil ,it conducts electricity .
- Iodine (non-metal), shiny surface and looks ,but it is a non-
metal.

13. Metal alloys
• Metal alloys : mixture of metals.
• Bronze is a mixture of copper and tin , used to bells as it makes ringing sound
when struck.
• Brass is a mixture of copper and zinc ,it is strong and corrosion resistant.
• Steel is mixture of iron ,carbon ,magnesium ,sulfur ,nickel.
• Stainless steel is a mixture of steel and chromium ,
used to make knives ,spoons and kitchen sinks.

14. The properties of materials
- There are a number of properties that
materials may have.

15. 1) Surface appearance
- Shiny, dull, rough or smooth

16. 2) Rigid
- Cannot be bent or squashed.
- Example: Rock

17. 3) Flexible
- Can be bent or squashed.
- Example: Flexible piece of wood
(Used as bows)

18. 4) Hard or soft
- Usually hard materials are rigid and
soft materials are flexible.

19. 5) Malleable
- Materials that can be shaped by
hammering or pressing.
- Example: Gold, silver and copper are
malleable

20. 6) Brittle
- Materials that break suddenly when
they are bent or hit.
- Example: Biscuit or chocolate bar

21. 7) Absorbent
- Materials have holes in their surface to
let the water pass through and have
spaces inside where the water can
collect.
- Some rocks (sandstone and limestone)
have gaps(pores) they are porous.

22. 8) Waterproof
- Materials that do not pass water
through.
Water resistant Water repellent
- Made of fibres.
- There are holes between the
fibres (water passes through)
- Fibres are coated with
silicones (does not allow
water to be absorbed)
- Used to make: Umbrellas,
outdoor jackets and trousers
- Do not have any holes in it
through which water can
pass
- Used to make: Wellington
boots

23. 9) Transparent
10) Translucent
11) Opaque
- Lets light pass through it (can see objects
clearly through it).
- Lets some of the light pass through
- Do not let the light pass through

24. 12) Heat
conductor
13) Heat
insulator
- Allows heat to pass through
- Does not allow heat to pass through

25. 14) Electrical
conductor
15) Electrical
insulator
- Allows electricity to pass through
- Does not allow electricity to pass
through

26. Property profile
- A description of a material in term of
its properties is called a property
profile.