Controlled Candle Experiments

To see which type of wax burns the fastest Ali, Will and Torah measure the start and finish weight of candles made from different types of wax. Identify the controlled variables.

• length of wick

• Type of wax

• Change in weight of the candle

• Amount of time candle is burning for

To investigate if a different amount of candles makes a difference in heating up the water, Alexander and Kyan use different numbers of tealight candles to heat a beaker of water. Identify the controlled variables.

• number of candles

• volume of water

• time taken to reach 40 degrees

• distance between candle and beaker

To investigate whether the amount of air available to a candle effects the time it burns for, Kate and Chloe uses a beaker to cover a candle and record the amount of time the candle takes to extinguish. Identify the controlled variables.

• Type of gas in the beaker

• Candle used

• Size of beaker covering candle

• Amount of time taken for candle to extinquish

To investigate whether the amount of air available to a candle effects the time it burns for, Hunter uses a beaker to cover a candle and records the amount of time the candle takes to extinguish. Identify the controlled variables.

• Size of candle

• Type of wax

• Size of beaker covering candle

• Amount of time taken for candle to extinquish

To investigate whether the amount of air available to a candle effects the time it burns for, Destiny-Lee and Mia uses a beaker to cover a candle and records the amount of time the candle takes to extinguish. They repeat the experiment 3 times for each size of beaker and average their measurements. The reason an experiment is repeated is to

• make the experiment take a long time

• check if the experiment is reliable

• improve the reliability of the experiment

• have more practice lighting matches

To investigate whether the diameter of a candle effects the rate at which it burns, Zachary burns three different candles and records the height of the candles after a period of time. Identify the controlled variables.

• starting height of candles

• Type of wax

• diameter of candles

• amount of time the candles are burning

To see which type of wax burns the fastest Ivy and Umayma calculate the change in weight of candles made from different types of wax after burning them for 10 minutes. They found that the weight of candles didn't change. How could they improve/change their experiment?

• change the size of the candles they are using

• try blowing on the candles to make them burn faster

• burn the candles for a longer period of time

To see which type of wax melts faster, Olivia lights a variety of candles at the same time and records the order in which the candles reach a fully melted state. Select the controlled variables for this experiment.

• Volume of wax in each candle

• Length of wick

• Type of wax

• Amount of time taken to melt

• Shape of each candle

To see if the size of a candle effects the rate at which a candle burns, Chris and Minh measure the start and finish weight of different sized candles. What variables need to be controlled?

• the start weight of the candle

• the shape of the candle (round or square)

• the type of wax

• the length of the wick