Mortar and pestle
A mortar and pestle is a heavy bowl with a club-shaped stick for grinding.
What is it for?
It crushes crystals and lumps into a fine powder, which helps them dissolve or react faster.
How to use it
Put a small amount in the bowl, then press and twist the pestle round and round instead of hitting hard.
🥽 Safety tip: Only grind things a grown-up says are safe to grind, because some chemicals can react when they are crushed.
Fun fact from Fizzy: People have used mortars and pestles for thousands of years to grind grain, herbs and spices.
Why grinding helps
A big lump only reacts on its outside. When you grind it into powder, there are many more tiny surfaces touching the liquid, so it dissolves or reacts much faster. Chemists call this increasing the surface area.
Lab mortars and pestles are usually made of porcelain, a hard, smooth kind of pottery. Some are made of stone, agate or glass, which do not wear away into the powder.
Where you would see one
Chemists use them to prepare samples, and pharmacists once used them to make every medicine. That is why a mortar and pestle is still a symbol of pharmacies in many countries. Cooks use them to grind spices and make pastes.