Elements, compounds, chemical equations

1. Elements, compounds
and mixtures
Chapter 10
(Chemistry)
Part 1

2. Pure Substances
• A sample of matter that has definite
chemical and physical properties.

3. Elements
• pure substance that cannot be separated into
simpler substance by physical or chemical means.

4. Mixtures
• A combination of two or more pure
substances that are not chemically combined.
• substances held together by physical forces,
not chemical
• No chemical change takes place
• Each item retains its properties
in the mixture
• They can be separated physically
Chem4kids.com

5. Compounds
Pure substance composed of two or
more different elements joined by
chemical bonds.
– Made of elements in a specific ratio
that is always the same
– Has a chemical formula
– Can only be separated by
chemical means, not physically

6. Can you identify the
following?
You will be shown a series of photos. Tell if each
photo represents an item composed of an element,
compound, or mixture.
Review:
• An element contains just one type of atom.
• A compound contains two or more different atoms
joined together.
• A mixture contains two or more different
substances that are only physically joined together,
not chemically.
– A mixture can contain both elements and compounds.

7. Element, Compound, or Mixture?
Rocks

8. Element, Compound, or Mixture?
Rocks

9. Element, Compound, or Mixture?
Copper

10. Element, Compound, or Mixture?
Copper

11. Element, Compound, or Mixture?
Jelly Beans

12. Element, Compound, or Mixture?
Jelly Beans

13. Element, Compound, or Mixture?
Table Sugar

14. Element, Compound, or Mixture?
Table Sugar

15. Element, Compound, or Mixture?
Diamond

16. Element, Compound, or Mixture?
Diamond

17. Element, Compound, or Mixture?
Tea

18. Element, Compound, or Mixture?
Tea

19. Element, Compound, or Mixture?
Salt

20. Element, Compound, or Mixture?
Salt

21. Element, Compound, or Mixture?
Neon Gas

22. Element, Compound, or Mixture?
Neon Gas

23. Element, Compound, or Mixture?
Salad

24. Element, Compound, or Mixture?
Salad

25. Element, Compound, or Mixture?
Pure Water

26. Element, Compound, or Mixture?
Pure Water

27. Chemical reactions and equations.
- Chemists use equations to describe a chemical reaction.
- The equations save time and space.
- The simplest equations are word equations.

28. - Substances that take part in a reaction are called the reactants.
- The substances formed as a result of the chemical reaction are called the
products.
- In an equation the reactants are written on the left-hand side of the
equation and the products are written on the right-hand side.
- If there are two or more reactants or products in the equation they are
linked together by (+) sign.

30. Chemical names
- Chemists use equations to describe a chemical reaction.
- The equations save time and space.
- The simplest equations are word equations.

31. How are compounds named? Prefix or suffix
1st part Name of the1st element
Ex. Carbon
Iron
Sodium
2nd part Name of 2nd element
If 2nd element is not joined to other elements Suffix -ide is used
Ex. Iron + Sulphur Iron sulfide
Sodium + Chlorine Sodium chloride
If the 2nd element is more that one atom Prefix di- (two)
tri- (three)
Ex. Carbon dioxide
Sulphur dioxide
If 2 elements are joined to the 1st element 2nd name is a mixture of the 2 elements
Ex. Sodium Hydroxide
If the 2nd elements is joined to oxygen atoms Suffix -ate is used
Ex. Calcium carbonate
Ferrous sulphate

32. Compound Description and uses
Calcium Oxide
(Quicklime)
A white solid used to produce limelight
Carbon dioxide A colourless gas produced in respiration
Copper oxide A black pigment used to colour pottery
Sulphur dioxide A colourless gas produced when fossil fuels are
burnt
Potassium hydroxide - A colourless solid used in soap making
- Makes an alkaline solution used in laboratories
Calcium hydroxide - A white solid used in the treatment of sewage and
drinking water.
- Used to make limewater for laboratory tests
Sodium Hydroxide - A colourless liquid used in soap making
- Makes an alkaline solution used in laboratories
Sodium chloride A white crystalline solid also known as common
salt

33. Compound Description and uses
Potassium chloride A white crystalline solid used in making fertiliser
Calcium chloride - A white solid which absorbs water vapour from
the air.
- Used to keep materials dry.
Calcium sulfate - White solid
- Used to make plaster of Paris
Copper sulphate Can form a white powder or bright blue crystals
Calcium carbonate - A white solid
- A component of snail shells and egg shells
present in large amounts in limestone.
Copper carbonate A blue green solid which can form the mineral
called malachite