Chemistry is a branch of Science. Science is basically the study of living and non-living things. The branch of science that studies living things is called Biology.
The branch of science that studies non-living things is called Physical Science.
Physical Science is made up of:
- Physics- the study of matter in relation to energy
- Chemistry– the study of the ,composition of matter.
Chemistry is thus defined as the branch of science that deals with the structure composition, properties and behaviour of matter.
Basic Chemistry involves studying:
States/phases of Matter
Matter is anything that has weight/mass and occupies space/volume. Naturally, there are basically three states of matter.
- Solid-e.g. soil, sand, copper metal, bucket, ice.
- Liquid e.g. water, Petrol, ethanol/alcohol, Mercury (liquid metal).
- Gas- e.g. Oxygen, Nitrogen, Water vapour.
A solid is made up of particles which are very closely packed. It thus has a definite/fixed shape and fixed/definite volume/occupies definite space. It has a very high density.
A liquid is made up of particles which have some degree of freedom. It thus has no definite/fixed shape. It takes the shape of the container it is put.
A liquid has a fixed/definite volume/occupies a definite space. A gas is made up of particles free from each other. It thus has no definite/fixed shape.
It takes the shape of the container it is put. It has no fixed/definite volume/occupies every space in a container.
Separation of a Mixture
A mixture is a combination of two or more substances that can be separated by physical means.
Simple methods of separating mixtures at the basic chemistry level include
- Sorting/picking- this involves physically picking one pure substance from a mixture with another/other. e. g. sorting maize from a maize beans mixture.
- Decantation– this involves pouring out a liquid from a solid that has settled/sunk solid in it. e. g. Decanting water form sand.
- Filtration– this involves sieving /passing particles of a mixture through a filter containing small holes that allow smaller particles to pass through but do not allow bigger particle to pass through.
- Skimming- this involve scooping floating particles. e.g. cream from milk
Metals and non-metals
Metals are shiny, ductile(able to form wires), malleable (able to form sheet) and coil without breaking. E.g. Iron, gold, silver, copper.
Mercury is the only liquid metal known. Non-metals are dull, not ductile (do not form wires), not malleable (do not form sheets) and break on coiling/brittle. E.g. Charcoal, Sulphur, plastics.
Conductors and Non-Conductors
- A conductor is a solid that allows an electric current to pass through.
- A non-conductor is a solid that does not allow an electric current to pass through.
- All metals conduct electricity. All non-metals do not conduct electricity except carbon and graphite.
Drugs
A drug is a natural or synthetic/man-made substance that, when taken, changes/alters the body’s functioning. A natural or synthetic/man-made substance that,, when taken changes/alters the abnormal body functioning to normal is called medicine.
Medicines are thus drugs intended to correct abnormal body functions.. Medicines should therefore be taken on prescription and according to a dosage.
A prescription is a medical instruction to patient/sick person on the correct type of medicine to take and the period/time between one intake to the next.
A dosage is the correct quantity of drug required to alter the abnormal body function back to normal. This is called treatment.
It is the professional work of qualified doctors/pharmacists to administer the correct prescription and dosage of drugs/medicine to the sick.
Prescription and dosages of drugs/medicines for the sick use medical language.
Example
- 2 x 4; means “2” tablets for solid drugs/a spoonful for liquid drugs taken “4” times for a duration of one day/24 hours, and then repeated and continued until all the drug given is finished.
- 1 x 2; means “1” tablet for solid drugs/a spoonful for liquid drugs taken “2” times for a duration of one day/24 hours and then repeated and continued until all the drug given is finished.
Some drugs need minimal prescription and thus are available without a pharmacist’s/doctor’s prescription.
They are called Over The Counter (OTC) drugs.
OTC drugs used to treat mild headaches, stomach upsets, common cold include:
- Painkillers
- Anti-acids
- Cold/flu drugs.
All medicines require the correct dosage. When a prescription dosage is not followed, this is called drug misuse/abuse.
Some drugs are used for purposes other than those intended.
This is called drug abuse. Drug abuse is when a drug is intentionally used to alter the normal functioning of the body.
The intentional abnormal function of the drug is to make the victim have a false feeling of well-being. The victim lacks both mental and physical coordination.
Some drugs that induce a false feeling of well-being are illegal. They include heroin, cocaine, bhang, mandrax and morphine.
Some abused drugs which are not illegal include: miraa, alcohol, tobacco, sleeping pills.