O Level Science Notes Archives - Page 13 of 33 - Free ZIMSEC & Cambridge Revision Notes

Effects of population growth on natural resources

By garikaib|2025-02-12T09:00:15+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Environmental degradation in Epworth. Image credit newsday.co.zw ZIMSEC O Level Combined Science Notes: Population and natural resources

Environmental Effects

Soil erosion
Deforestation
Desertification
Reduced soil fertility

Social Effects

Overcrowding
Criminal activities
Immorality
Poor health services
Poor education facilities
General increase in poverty

To […]

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Safety wear

By garikaib|2025-02-12T09:10:16+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Safety Equipment Image credit nexomundo.com ZIMSEC O Level Combined Science Notes: Safety wear

Pesticides are dangerous and need to be handled with care.
The following equipment ought to be used when handling chemicals depending on the instructions of each chemical’s label and its usage directions.

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Experiment: Do plants release carbon dioxide when they respire?

By garikaib|2025-02-12T09:45:40+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Potted plant. Image credit artificialplantsandtrees.com ZIMSEC Combined Science Revision Notes: Do plants release carbon dioxide when they respire?

Aim: To determine whether all living things, including plants, release carbon dioxide when they respire.

Materials: bell jar or a large container, 3 boiling tubes/flasks glass or rubber tubing, lungs, suction […]

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Investigating water loss in plants

By garikaib|2025-02-12T09:15:44+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Transpiration occurs mainly through the leaves. Image credit desk7.net ZIMSEC O Level Combined Science Notes: Investigating water loss in plants

Aim: To determine how plants loose their water

Materials: plants or branches from plants, weighing balance, containers, water, oil/Vaseline.

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Ecosystems: The soil

By garikaib|2025-02-12T09:39:32+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Soil profile. Image credit nesoil.com ZIMSEC O Level Combined Science Notes: Ecosystems: The soil

Soil is an important part of the ecosystem
It is a critical component of life on earth and agriculture
Soil thickness varies from a few millimeters to a several meters in places
Animals and plants […]

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The Carbon cycle

By garikaib|2025-02-12T09:02:20+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

The carbon cycle. Image credit windows2universe.org ZIMSEC O Level Combined Science Notes: The Carbon cycle

Carbon dioxide in the atmosphere is the source of carbon in ecosystems
Plants remove carbon dioxide from the air during photosynthesis and use it to build food compounds
Animals obtain the carbon […]

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Experiment: to show the cooling effect of methylated spirits

By garikaib|2025-02-12T09:13:32+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

A bottle of methylated spirit. Image credit wilko.com ZIMSEC O Level Combined Science Notes: Experiment: to show the cooling effect of methylated spirits

Material: cotton wool,methylated spirits

Method

Dip a small piece of cotton wool into the methylated spirits
Rub some of […]

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Common metals and their uses

By garikaib|2025-02-12T09:24:03+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Copper wires. Image credit globalminingobserver.com Copper wires. Image credit globalminingobserver.com ZIMSEC O Level Combined Science Notes: Common metals and their uses

Common metals include:
aluminium
iron and
copper

Copper

is a soft, malleable and ductile metal with very high heat and electrical conductivity
has a reddish-orange color
It is used in thermostat, in electrical wiring
It is also […]

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Experiment: The properties of acids

By garikaib|2025-02-12T09:00:53+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Universal paper can be used to test the acidity of a solution. Image credit MediaWiki ZIMSEC O Level Combined Science Notes: Experiment: The properties of acids

Aim: Investigating the properties of acids

Materials: Dilute hydrochloric acid, vinegar, lemon juice, […]

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Experiment: investigating reversible reactions
Gallery
Experiment: investigating reversible reactions

Notes, O Level Science Notes, Ordinary Level Notes

Experiment: investigating reversible reactions

By garikaib|2025-02-12T09:19:15+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Experiment: investigating reversible reactions

Aim: Investigating reversible reactions

Materials: boiling tube, test tubes, copper sulphate crystals,solid ammonium chloride, red litmus paper, blue litmus paper, dilute hydrochloric acid, sodium hydroxide solution, potassium chromate solution, tongs

February 2025