Chemistry Around Us questions

43 fact-checked questions — tap any to predict the answer, then read why.

Why can pyrite-rich ground exposed by thaw keep generating acid after the first flush of water has passed?
Why can IFRA restrict a natural essential oil ingredient, not just synthetics?
Some long-wear perfumes keep citrus noticeable for hours. What breaks the old pyramid?
Why can one perfume smell different on warm skin than on a paper strip?
A fixative can make perfume last without being the loudest smell. What is it doing?
Why does spraying perfume on a warm wrist smell stronger at first but fade faster?
Why do citrus openings fade before woody notes in many perfumes?
Why does an alcohol-based perfume often bloom loudly right after spraying?
Why do perfume top notes arrive first, then vanish before the deeper smell?
Why does old, opened beer taste flat and stale?
Why do some beers smell skunky?
Why do apples turn brown when cut?
Why does baking soda fizz with vinegar?
Why does milk curdle when sour?
Why does yeast make bread rise?
What causes silver jewelry to turn black over time?
Why does hydrogen peroxide bubble?
What causes iron to rust?
Why does soap clean?
Why do things smell different?
Why does dry ice smoke?
Why does oil float on water?
Why does alcohol evaporate quickly?
Why does bleach remove stains?
Why do fireworks have different colors?
Why are soap bubbles always round?
Why does milk turn sour?
Why do onions make us cry?
Why does fire need oxygen?
Why does water boil at 100°C?
Why do fizzy drinks bubble?
Why do batteries produce electricity?
Why does salt melt ice?
Why can you blow bubbles with soapy water but not plain water?
Why does bread rise when baking?
Why does rust form on iron?
Why does baking powder make cakes rise?
Why does soap clean dishes?
Why do baking soda and vinegar react?
Why does copper turn green?
Why does popcorn pop?
Why does metal feel colder than wood?
Why does sugar dissolve in water?

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