Q 01/05

Chemically speaking, fire is the rapid what of a fuel?

A) Reduction

B) Oxidation

C) Fermentation

D) Sublimation

Answer · why

B) Oxidation

Combustion is exothermic, releasing heat and light; the flame appears once the fuel reaches its ignition temperature.

Q 02/05

What are the three elements of the fire triangle?

A) Carbon, hydrogen and oxygen

B) Spark, wood and wind

C) Heat, light and smoke

D) Heat, fuel and an oxidising agent

Answer · why

D) Heat, fuel and an oxidising agent

The fire tetrahedron adds a fourth: the chemical chain reaction that keeps it going.

Q 03/05

What shape does a flame take in the microgravity of space?

A) Teardrop

B) Flat

C) Spherical

D) Ring-shaped

Answer · why

C) Spherical

Without convection it also burns bluer and more efficiently, and NASA found more soot gets fully burned.

Q 04/05

When a hydrocarbon flame gets enough air, what colour does it turn?

A) Blue

B) Yellow

C) Red

D) Green

Answer · why

A) Blue

The yellow of a candle comes from glowing soot; with full combustion no soot or carbon monoxide forms.

Q 05/05

Which French chemist proposed in 1777 that combustion involves a component of air he named oxygène?

A) Joseph Priestley

B) Antoine Lavoisier

C) Robert Boyle

D) Georg Stahl

Answer · why

B) Antoine Lavoisier

His theory replaced phlogiston, which had dominated chemistry for nearly two centuries.