Can you un-boil an egg?
Melt chocolate and it sets again in the fridge. Freeze water and it melts back. Those are reversible changes: nothing new is made. Boil an egg, though, and the runny white turns solid for good: its proteins unfold and tangle together into something new. Can you sort the changes in the word bank?
Asked by calcali
1 answer
Reversible: melting ice, dissolving salt (let the water evaporate and the salt is left behind), freezing juice. Not reversible: burning wood, toasting bread, iron rusting: each one makes new substances. (Scientists have untangled boiled egg-white proteins with a special spinning machine, but not in a kitchen!)
by calcali