2B

Task B1 The use of chemical based on their physical properties Copy the title

Electrical conductivityThermal conductivityMelting points Boiling pointSolubilityViscosity These materials allow electricity to pass through them. metals are known as good conductors and non metals are know as insulators (bad conductors) These materials allow heat to pass through them. metals are good conductors of heat, non metals are good thermal insulators, such a wood. Is the temperature at which a chemical turns from a liquid into a gas Is the temperature at which a chemical turns from a solid into a liquid Some solid substances (solute) can dissolve into liquid (solvent). For example sugar (solute) dissolves into water (solvent) to form a solution. Measures how easily liquid flows. Thicker liquids are more viscous (they don’t flow well) P4 Colour the statements that match in one colour The meanings of the key words

Electrical conductivityThermal conductivity Melting pointsBoiling point SolubilityViscosity These materials allow electricity to pass through them. metals are known as good conductors and non metals are know as insulators (bad conductors) These materials allow heat to pass through them. metals are good conductors of heat, non metals are good thermal insulators, such a wood. Is the temperature at which a chemical turns from a liquid into a gas Is the temperature at which a chemical turns from a solid into a liquid Some solid substances (solute) can dissolve into liquid (solvent). For example sugar (solute) dissolves into water (solvent) to form a solution. Measures how easily liquid flows. Thicker liquids are more viscous (they don’t flow well) The meanings of the key words Electrical conductivityThermal conductivity Melting pointsBoiling point SolubilityViscosity These materials allow electricity to pass through them. metals are known as good conductors and non metals are know as insulators (bad conductors) These materials allow heat to pass through them. metals are good conductors of heat, non metals are good thermal insulators, such a wood. Is the temperature at which a chemical turns from a liquid into a gas Is the temperature at which a chemical turns from a solid into a liquid Some solid substances (solute) can dissolve into liquid (solvent). For example sugar (solute) dissolves into water (solvent) to form a solution. Measures how easily liquid flows. Thicker liquids are more viscous (they don’t flow well)

The reasons why different materials are used in mobile phones Mobile phones contain different types of materials Copper wiring- copper is a good conductor of electricity Silver- used in the switch board. Silver is an even better conductor of electricity. It lasts for a long time Gold- used to plate the surfaces of a circuit board. Excellent electrical conductor and does not corrode (wear away) Tantalum- enables scientists to make mobile phones very small/thin MetalHardnessElectrical conductivity CorrosionCost (£/Kg) Copper Corrodes slowly78 Silver Corrodes slowly650 Gold Very corrosion resistant 32,990 Tantalum Corrosion resistant below 300 C 317 M4 Copy the title And turn into a paragraph

Task B2 The use of chemical based on their chemical properties Copy the title

Use of a chemical in Air bags Chemical Name: Sodium azide Airbags inflate due to a chemical reaction. They contain sodium azide. It is not reactive until it is heated up. During a collision the airbag is heated up and the sodium azide produces sodium and nitrogen gas. The Nitrogen gas fills the airbag Word and symbol equation: sodium azide  sodium + nitrogen 2NaN 3  2Na (s) + 3N 2 (g) All of these chemicals are non toxic. This is important so that they don’t harm human health Some chemicals are used because of their chemical properties… Use of a chemical in welding Chemical Name: Argon Argon is not reactive (inert) and is very stable. Because argon has a full outer shell of electrons (M4) When making a metal object, you need to weld (join) the bits of metal together. You need a lot of heat to weld The argon is used to stop the metal parts from burning during welding Use of a chemical in computer chips Chemical name: Silicon Is used to make the computer chips Silicone is a semi conductor which means you can control the amount of electricity flowing through it. Use of a chemical in fire extinguishers Chemical name: Carbon dioxide Used in fire extinguishers. Fire needs oxygen to burn. Carbon dioxide contains oxygen but because it has strong covalent bonds, it doesn’t break up into carbon and oxygen easily Carbon dioxide does not things burn. Smothering a fire with carbon dioxide will put out the flame P5 and M4 Turn into a paragraph