1. Introduction To Chemistry
A Motivational Lesson

2. CHEMISTRY
ELEMENT,
COMPOUND
AND
MIXTURE

3. ELEMENT Non-Metal Metal (l) (l) (s) (g) (s)
(g) – gas (l) – liquid (s) - solid

4. Examples of Metals
( Sodium ) Na
Use :
Sodium Lamp

5. The periodic table Increasing metallic characterBe B C N O F Ne Na Mg Al Si P S Cl Ar
Increasing metallic character K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Ac Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
Metals
Metalloids
Nonmetals
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6. What is an element ? Element A chemical substance Simplest substance
Cannot be decomposed to a simpler substance
Built up from one type of atoms only

7. Use : Electric Conductor
Copper Cu
Use : Electric Conductor

8. What is a Compound ?
A Chemical
Consists of 2 or more elements chemically combined
Chemical Bond between the particles

9. Sodium Chloride
Use : Flavor for Food
Constituents : Na , Cl

10. Glucose
Use : Carbohydrates
Constituents : H , C , O

11. What is a Mixture ?
Substance consisting of 2 or more substances physically combined together
Components : Elements or/and compounds
Components can be separated by physical means

12. Mixtures
Homogeneous Mixture – composition and properties are uniform (sometimes called a solution)
Air – principal components include O2, N2 & CO2
Vodka – principal components are EtOH & H2O
Brass – solid solution of Cu and Zn
Ruby – solid solution of Al2O3 and Cr2O3
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13. Mixtures
Heterogeneous Mixture – composition and properties are non-uniform
Chocolate Chip Cookie – chocolate, sugar, dough, etc.
Concrete – cement, sand, aggregate
Vomit – Depends upon previous intake of food and drink
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14. Air– Oxygen, Nitrogen, Carbon dioxide, water vapor etc
Examples of Mixtures
Air– Oxygen, Nitrogen, Carbon dioxide, water vapor etc

15. Components : Lactose, water, proteins, vitamins, minerals etc
Milk
Components : Lactose, water, proteins, vitamins, minerals etc

16. Properties of Matter
Types of matter are distinguished by their properties
There are two categories of properties that concern us:
Physical properties
Chemical properties
If two samples of matter have the same properties, they must be the same substance
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17. Changes in Matter Gas Sublimation Evaporation Deposition Condensation
Chemical
Physical
Gas
Sublimation
Evaporation
Deposition
Condensation
Changes don’t have to be on a macro scale - at the very trace analysis scale can also get changes at ppb (109) and ppt (1012) level
Melting
Solid
Liquid
Freezing
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18. Properties of Matter
Physical properties –the identifying characteristics of matter
Some properties can be readily measured with our senses
odour
Colour
Instruments are needed to measure other properties
electrical resistivity
compressibility
hardness
melting point
radioactivity
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19. Changes in Matter Physical change
Substance changes physical appearance without altering its identity
e.g. changes of state
ice melting to form water
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20. Physical properties METALS NON METALS good conductors of electricity
Ductile
malleable, lustrous
typically: solid
high melting point
good conductors of heat
NON METALS
poor conductors of electricity
not ductile
not malleable
solid, liquid or gas
low melting point
poor conductors of heat
You have already been through the basic trends in the periodic table in your 2nd lecture. These are some general physical and chemical properties, we will look at some of these in some more detail. These are really the 2 categories that concern us: Physical and chemical properties.
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21. Changes in Matter Chemical changes (or chemical reactions)
Substances transform into chemically different substances
i.e. identity changes
e.g. decomposition of water
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