[SEC 2]General Science WA2

• The insulated cap reduces the rate of heat loss by conduction.
• The insulated support reduces the rate of heat loss by conduction.
• The vacuum between the glass walls prevents heat loss by conduction. Conduction cannot occur in a vacuum.
• Keeping the cap tightly screwed reduces the rate of heat loss by convection.
• The silvered inner walls reflect heat and reduce heat loss by radiation.
• During the day, the land heats up more readily than the sea.
• 1. The sun heats up the land, which in turn warms the layer of air above it. The warmer air is less dense and rises.
• 2. The cooler air above the sea moves into replace the air above the land. This movement of air current sets up a sea breeze.
• We can use indicators to help us to as they change colour in the presence of an acid or an alkali.
• An acidic solution turns blue litmus paper red. It has no effect on red litmus paper.
• An alkaline solution turns red litmus paper blue. It has no effect on blue litmus paper.
• A neutral solution has no effect on red or blue litmus paper.
• Rusting is an oxidation reaction that is unwelcome and occurs rapidly in humid climates.
• Iron + oxygen + water -> rust
• Ways to prevent rusting:

  • Painting
  • Oiling
  • Galvanising, which involves coating iron with a protective layer of zinc.
  • Drying
• Heater:

  1. Cool air sinks to the bottom of the room.
  2. Air that is warmed rises to the top of the room. This forms convection currents in the air, which warm up the entire room.
• Behavioural adaptations: Dig/lives in burrows for protection against predators [and to keep itself cool.]