Experiment: Fill the Glass with Water Using a Candle

Supplies

• Shallow dish or plate

• Small candle (tealight works best)

• Matches or lighter (STAFF USE ONLY)

• Clear glass (must fit over the candle)

• Water

• Optional: food colouring (for visibility)

Safety First (Staff to read before starting)

• This experiment must be led and controlled by a staff member

• Only staff are to light and extinguish the candle

• Children must stay at arm’s length from the flame

• Keep water nearby at all times

• Never leave the candle unattended

• Ensure long hair is tied back and sleeves are clear

  
  

  Steps

• Place the candle upright in the centre of the dish.

• Pour a small amount of water into the dish (enough to cover the base, not the candle).

• Light the candle (staff only).

• Carefully place the glass upside down over the candle, with the rim sitting in the water.

• Watch closely as the candle flame goes out and water is drawn up into the glass.

• Once the candle is fully out and cool, remove the glass.

What to Observe

• The flame goes out after a few seconds

• Water rises up into the glass

• The higher the flame, the more water is pulled in

Explain It Simply to Children

“When the candle is burning, it uses up the air inside the glass. When the flame goes out, the air cools and shrinks, pulling the water up into the glass.”

Discussion Prompts

• What do you think will happen before we start?

• Why do you think the water moved?

• What would happen if we used a bigger glass?