Unit 4 Oxford 6th grade. Matter, types of matter, changes of matter, physical changes and chemical changes: oxidation, combustion, fermentation. Types of mixtures, separation of mixtures.
2. PREVIOUS KNOWLEDGE
• Matter is anything that has a mass and occupies a space= volume.
• Mass is the amount of matter (measured in kg, g, mg....)
• Volume is the space it takes up (measured in dm3, m3, liters...)
• Matter can be natural or man-made and exists in 3 states: solid, liquid and gas
• Matter is made up of atoms
• Atoms have a nucleus and a cloud of electrons.
• In the nucleus there are protons and neutrons.
• In the cloud there are electrons
• A molecule is made when two or more atoms join together
Link to
my video
about Matter 1
4. 1. PURE SUBSTANCES AND MIXTURES
SUBSTANCES
PURE
ELEMENTS COMPOUNDS
MIXTURES
HOMOGENEOUS HETEROGENEOUS
Pages 66,
67
5. CLASSIFICATION OF SUBSTANCES
• PURE SUBSTANCES: Made up of only one type of molecule
• Element: made up of only one type of atom: O2(oxygen), Fe(iron), Au (gold)…. They are in
the periodic table of elements (link to the periodic table of elements)
• Compound: made up of a combination of elements with a chemical formula: H2O (water)
CO2 (carbon dioxide), NH3 (ammonia)…..with chemical bonds
• MIXTURES: contains two or more different substances that are not chemically
combined (they don’t form molecules, they are just together)
• Homogeneous mixtures: the substances are so well mixed that they cannot be distinguished.
The appearance is homogeneous (same color and texture in all their parts) Air, sea water....
• Heterogeneous mixtures: the different substances are not equally distributed, so they can be
distinguished. There are variations in the color or texture. Food, cement, sand, water and
oil....
6.
7. SOLUTIONS:
A type of
homogeneous
mixtures
A solution is a homogeneous mixture that
has a liquid and a substance dissolved in it
SOLUTION: solute + solvent
SOLVENT: liquid of the solution. It is in
more amount than the solute
SOLUTE: can be liquid, solid or gas and is
dissolved in the solvent. It is in less amount
8. 2. SEPARATING MIXTURES
• There are several techniques such as:
• FILTRATION
• DISTILLATION
• EVAPORATION
• MAGNETS
• ….....
Pages 68,
69
9. FILTRATION
• To separate an
insoluble solid from a
liquid. The filter retains
the solid.
• Example: sand and
water.
Link to
video about
filtration
10. EVAPORATION
• Separates a soluble
solid from a liquid that
evaporates.
• Example: salt and water
Link to
video about
evaporation
11. DISTILLATION
• To separate two liquids
with different boiling
point. The first one
evaporates, the gas moves
up and then passes
through the condenser
where it becomes liquid
again.
• Example: water and
alcohol
Link to video
about
distillation
12. SOME
CHEMICAL
CHANGES
• New molecules are made
• Substances change their
composition
• Matter changes forever (usually, some
changes are reversible though)
Remember that in a chemical
change.....
• COMBUSTION
• OXIDATION
• FERMENTATION
EXAMPLES
13. 3. COMBUSTION
FUEL OXYGEN ENERGY
INICIAL
HEAT
CARBON
DIOXIDE
ASH
SMOKE
WATER
Link to my video
about Combustion
Pages
70,71
15. PROBLEMS FROM
COMBUSTION
• Combustion of most fuels produces
Carbon dioxide that increases the
GREENHOUSE EFFECT and produces
GLOBAL WARMING
• Combustion of coal, petrol or diesel
produce particles that pollute the air and
produce RESPIRATORY ILLNESSES.
• Combustion of coal and diesel can produce
sulphur dioxide that produces ACID
RAIN.
17. RUSTING
• When Iron is exposed to oxygen
and moisture, loses the electrons.
• Effects:
• Change of color (red or orange)
• Becomes brittle (fragile) and weak
• Solution: paint to form a barrier
Link to video
about rusting
18. BROWNING
IN FRUIT
• Some fruits are reducing
agents.
• The surface of the fruit
loses electrons.
• Effects:
• Changes in color and
taste
• Solution: protection of
the skin. Cover with a film
or lemon.
Link
to experiment about
browning
19. FERMENTATION
• Chemical change made by microorganisms such as:
• YEAST (levadura)
• BACTERIA
• Discovered thousands of years ago
• Gives us many different food and drink:
• Yogurt, cheese, wine, bread, cider....
• Microorganisms feed on the sugar of the food
producing other substances that change the properties of
the food.
Pages 74,
75
Type of yeast that makes bread
Type of bacteria that makes yogurt
Link to my video
on Fermentation
20. Examples of food we make through
fermentation
Cider
(sidra)
Wine
Bread
YEAST
Yogurt
Cheese
BACTERIA
21. Wine and cider: Fermentation with yeast
Sugar
(grapes,
apples)
Yeast
Alcohol +
Carbon
dioxide
Link to how wine is
made
ENZYMES
Accelerate the process
22. Bread: fermentation with yeast
Link to how bread is
made
Flour and warm water: dough (masa)
Yeast consumes the starch (almidón) of the flour (a
type of sugar)
The yeast produces tiny Carbon dioxide bubbles
which makes the dough expand. (spongy bread)
BREAD RECIPE
(english bread)
BREAD RECIPE
(spanish bread)
23. Yogurt: fermentation with bacteria
Link to how to make
yogurt
Lactose turns into....
Lactic acid (tastes sour and acidic)
Bacteria (we add more) consume....
The lactose of the milk
FRESH MILK contains
Lactose (type of sugar) and Bacteria
