Introduction to Chemistry
ICSE Class 6 · Chemistry · Chapter 1
What this chapter covers
- Chemistry: what it is and why it matters
- How chemistry began and grew
- Great chemists and their work
- Chemistry in daily life
- Chemicals in industries
Key definitions
Chemistry is the branch of science that studies what things are made of, how they behave, and how they change into new things.
Alchemy is the old practice that tried to turn cheap metals into gold and to find a medicine that would let people live for ever.
Extraction is the process of getting a metal out of its ore.
Food processing is the changing of raw food into a form that is easier to store, cook or eat.
Key points
- Chemistry studies what things are made of, how they behave and how they change.
- Chemistry gives us clean water, food, medicines, cleaners, clothes and fertilisers.
- Alchemists failed to make gold, but their methods helped chemistry grow.
- Early people learnt to extract metals from ores and to make alloys such as bronze, brass and steel.
- The iron pillar near the Qutub Minar has hardly rusted in over 1,600 years.
- Lavoisier, Dalton and Mendeleev built modern chemistry through patient, honest work.
- Salt, sugar, vinegar and oil preserve food; talc, zinc oxide and starch are in talcum powder.
- Terylene is a synthetic fibre; paracetamol and aspirin are common medicines.
- Industries turn starting materials into products such as soap, detergents, dyes, plastics and fertilisers.
Questions answered
What is chemistry?
Chemistry is the branch of science that studies what things are made of, how they behave, and how they change into new things.
Name two things the alchemists tried to find.
The philosopher's stone, to turn cheap metals into gold, and the elixir of life, to let people live for ever.
What is an alloy? Give one example and say what it is made from.
An alloy is a mixture of a metal with other metals, or with a little carbon, made by melting them together. Brass is an alloy of copper and zinc.
Why is the iron pillar near the Qutub Minar famous?
It is over 1,600 years old and has hardly rusted, which shows the great skill of ancient Indian metal workers.
Match each chemist with his work: Lavoisier, Dalton, Mendeleev.
Lavoisier showed that matter is not lost in a change and named oxygen. Dalton said that everything is made of tiny atoms. Mendeleev arranged the elements in a table and left spaces for new ones.
Name two natural food preservatives used at home.
Any two of salt, sugar, vinegar and oil.
Name two things found in talcum powder.
Any two of talc, zinc oxide, starch and perfume.
Give one example of a synthetic fibre and one medicine used for fever.
Terylene (or nylon or polyester) is a synthetic fibre. Paracetamol is used for fever.