Ch.10.elements, compounds and mixtures

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. Elements Atoms Compounds Molecules

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 H 2 O CO 2 NaCl

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 Cu

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 C 12 H 22 O 11

15. Element, Compound, or Mixture? Diamond

16. Element , Compound, or Mixture? Diamond C

17. Element, Compound, or Mixture? Tea

18. Element, Compound, or Mixture ? Tea

19. Element, Compound, or Mixture? Salt

20. Element, Compound , or Mixture? Salt NaCl

21. Element, Compound, or Mixture? Neon Gas

22. Element , Compound, or Mixture? Neon Gas Ne

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 H 2 O

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.

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

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

31. Compound Description and uses Calcium Oxide (Quick lime) 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

32. 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