1. Lesson: Mixtures & Compounds

2. Science Differentiation in action A mixture is made of two or more substances mingled together but not chemically combined. Air is a mixture Sea water is a mixture

3. Science Differentiation in action Air contains: nitrogen oxygen carbon dioxide

4. Science Differentiation in action Sea-water contains: water salt The Dead Sea has a high concentration of salt.

5. Science Differentiation in action A compound is formed when two or more elements combine chemically. Carbon dioxide gas is a compound formed when one atom of carbon is combined chemically with two atoms of oxygen (CO 2 ). oxygen carbon

6. Science Differentiation in action A compound is formed when two or more elements combine chemically Water is a compound formed when one atom of oxygen is combined chemically with two atoms of hydrogen (H 2 O). hydrogen oxygen

7. Science Differentiation in action Examples of compounds Water (H 2 O) Carbon dioxide (CO 2 ) Magnesium oxide (MgO) Iron sulfide (FeS) How many atoms are in each molecule of the above compounds?

8. Science Differentiation in action Differences between mixtures and compounds MIXTURES Made of 2 or more substances COMPOUNDS Is a single substance Proportion of each substance may vary Proportion of each element is fixed Properties are the same as the properties of the substances mixed together Properties are different to the elements involved Generally easy to separateDifficult to separate

9. Science Differentiation in action A compound is a completely new substance with its own properties. Water (H 2 O) is a liquid that can put out fires. Yet, the elements that make it are very different. Hydrogen (H 2 ) is an explosive gas. Oxygen (O 2 ) is needed for burning. hydrogen oxygen

10. Science Differentiation in action Carbon dioxide (CO 2 ) is a colourless gas used to put out fires. Carbon (C) is a black solid. Oxygen (O 2 ) is needed for burning. oxygen carbon A compound is a completely new substance with its own properties.

11. Science Differentiation in action Magnesium oxide (MgO) is a dull white solid. Magnesium (Mg) is a soft shiny metal. Oxygen (O 2 ) is needed for burning. A compound is a completely new substance with its own properties.

12. Science Differentiation in action Iron sulfide (FeS) is a grey solid that is not attracted to magnets. Iron (Fe) is a metal that is attracted to magnets. Sulfur (S) is a bright yellow solid. A compound is a completely new substance with its own properties.

13. Science Differentiation in action 1. Is air a mixture or a compound? Review Questions 2. What elements is carbon dioxide made from? 3. Name one difference between a compound and a mixture. 4. Hydrogen is explosive and oxygen is needed for burning. What compound can both of these elements make?

14. Science Differentiation in action How could you check if a substance was an element or a compound? Question to think about! hydrogen oxygen