Sunshine State Standard

SC.D.1.4.1

Materials

an empty aquarium thin cardboard black bristol board or black carbon a small candle, an old rag, mathces, masking tape

What to do

1. Make a cover for the aquarium, with two holes, and also two fitting pipes that will act as chimneys, from the thin cardboard. 2. Cover the backside of the container withblack paper, so that the smoke currents can be more easily seen (use a spotlight if available). 3. Fix the candle under one of the holes in the bottom of the aquarium and light the candle. 4. Place the cover over the container and tape the edges airtight to it. 5. Make a smoke source from the rag (by burning it and letting it smolder) or light a cigarette, and hold the smoke close to chimney B (see sketch). 6. Let the smoke fall into chimney B (do not hold the smoke sources directly above the opening, but blow the smoke over the opening) and let the students observe the smoke currents.) Questions: 1. What makes the smoke fall in chimney B? 2. Why does the air rise through chimney A? 3. What is the purpose of the burning candle? 4. How can we create wind currents without the burning candle? 5. What places on earth can spot A' and B' be compared with?

Additional Information

EXPLANATION: The burning candle is a source of heat. It heats the air above and around the flame, and heated air rises. This makes the air rise through chimney A, and because air goes out of the container, air must replace it, and and this comes in through chimney B, taking the smoke with it. Spot A' can be compared with a hot place on earth (f.i. the tropics) and B' with a cold place (the poles). The air currents or winds are created this way between such places on earth. Instead of the candle we can also use an ice cube above chimney B'. Cold air will move down and create the came currents.

Submitted by

Julie Noren

Hillsborough County
Tampa, Florida