Chemistry is the branch of science that studies the composition, structure, properties and changes of matter. Everything around us — air, water, food, fuel and even our own bodies — is made of matter, so chemistry touches almost every part of daily life.
From alchemy to modern science
The roots of chemistry lie in ancient alchemy. Alchemists tried to turn ordinary metals into gold and to find a "potion of eternal life". They failed, but they invented useful apparatus and techniques such as distillation, filtration and crystallisation that chemists still use. In the 18th century, careful measurement of mass turned chemistry into a true experimental science; Antoine Lavoisier is often called the father of modern chemistry for showing that mass is conserved in a reaction.
Key idea / 要点
Chemistry became a modern science when scientists began to measure quantities and repeat controlled experiments, instead of relying on guesswork and magic.
Chemistry in industry and careers
Today chemistry supports many industries. Some examples:
- Medicine and pharmacy — designing drugs and analysing samples.
- Food technology — preservatives, additives and safe packaging.
- Petrochemicals — turning crude oil into fuels and plastics.
- Agriculture — fertilisers and pesticides for better crops.
- Environment — treating water and monitoring pollution.
Careers that use chemistry include chemist, pharmacist, chemical engineer, forensic analyst, food technologist and quality-control officer.
Worked example / 例题
A student sees "sodium benzoate" on a soft-drink label and wonders what it does. Using chemistry knowledge, she identifies it as a food preservative that slows the growth of microbes. This shows how understanding chemistry helps us make informed choices as consumers.
Remember / 记住
- Chemistry studies matter and its changes.
- Alchemy gave us early apparatus but was not a true science.
- Chemistry is central to medicine, food, fuel and the environment.