Uploaded March 2020 | Updated September 2026, 3 weeks ago
How to make a motor with a candle.
Equipment: candle, needles, glasses, tray, lighter.
Find the candle's center of mass, by balancing it on your finger, and then stick needles in both sides of the center point. Balance the candle between two glasses using the needles and light the candle at both ends. Watch as the motor begins!
When the wick burns, the candle's center of mass shifts constantly, and when a drop of paraffin falls from one end (A), its mass decreases and the other end (B) is then heavier. The flame at this end (B) then warms a bigger part of the candle and paraffin drips more intensively out of it. At some point, side A begins to outweigh side B and goes down. The oscillation amplitude of the paraffin motor increases gradually.
Amazing experiments are waiting for you in your MEL Chemistry subscription!
Warning! Only under adult supervision
How to make a motor with a candle.
Equipment: candle, needles, glasses, tray, lighter.
Find the candle's center of mass, by balancing it on your finger, and then stick needles in both sides of the center point. Balance the candle between two glasses using the needles and light the candle at both ends. Watch as the motor begins!
When the wick burns, the candle's center of mass shifts constantly, and when a drop of paraffin falls from one end (A), its mass decreases and the other end (B) is then heavier. The flame at this end (B) then warms a bigger part of the candle and paraffin drips more intensively out of it. At some point, side A begins to outweigh side B and goes down. The oscillation amplitude of the paraffin motor increases gradually.
Amazing experiments are waiting for you in your MEL Chemistry subscription!
Warning! Only under adult supervision







![Fake chemical cut
Oh, no! You slipped and cut your hand on a plastic knife! Wait, what…?
Equipment and reagents: iron(III) chloride, potassium thiocyanate, sodium fluoride, water, plastic knife, cotton wool, tweezers.
Prepare solutions of iron(III) chloride, potassium thiocyanate, and sodium fluoride by dissolving the respective reagents in water. Soak a cotton ball in the solution of potassium thiocyanate, then rub the cotton ball on your hand. Dip a plastic knife in the solution of iron(III) chloride and draw it gently across your palm. This creates a bloody “cut” on your hand! Treat it by wiping a cotton swab dipped in the sodium fluoride solution across the “wound.” Your hand is safe and sound!
Naturally, there was never any blood on your hand. What you observed was a chemical reaction that occurs between the solutions of potassium thiocyanate and iron(III) chloride. Thiocyanate ions and ferric ions form complex, blood-red compounds, the most well-known of which being iron(III) thiocyanate:
FeCl3 + 3KSCN=Fe(CNS)3 + 3KCl Adding sodium fluoride destroys the iron(III) thiocyanate complexes, and colorless hexafluoroferrate(III) [FeF6]3- ions form.
Fe(CNS)3 + 6NaF=Na3[FeF6] + 3NaCNS
Safety precautions: do not try it at home! Perform this experiment only under professional supervision. Fake chemical cut](https://i.ytimg.com/vi/pJyrLced5Iw/mqdefault.jpg)


