Jason

Practical 3 – ‘Convection Currents’

Conclusion Convection Currents- Part A

The hypothesis I had planned turned out correct. I predicted we would successfully observe the movement of convection currents. The crystal had released purple coloured dye into the water. The dye had spun around also rising in the water as the convection current. The dye had risen due to the fact that the heat caused the dye to become more lighter and less dense than the water.

Conclusion Convection Currents- Part B

The crystals did realeased dye into the water. The cold air from the bag of ice had pushed and caused the dye to sink to the bottom of the beaker where it circulated. The cold air had made the dye heavier and more dense than the water which is why the dye had fallen to the bottom of the beaker.

Questions

1. Explain what causes convection currents.

Convection currents are caused by activity between hot air and material and cold air and material. In the mantle hot air, liquids and molten rock rise whereas cool air, liquid and rock sink due to their higher density. When hot mantle rock comes into contact with relatively cold crust, it cools and sink. This is what causes convection currents in the mantle.

2. Use a diagram to clarify what a ‘hot’ current does.

3. Identify the direction of a ‘cold’ current.

A cold current sinks and travels in an anti-clockwise direction. The cold current is the opposite of a warm current which spins in a clockwise direction.