O Level Science Notes Archives - Page 22 of 33 - Free ZIMSEC & Cambridge Revision Notes

Molecules

By garikaib|2025-02-12T09:07:27+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Molecules of carbon, oxygen, hydrogen and water ZIMSEC O Level Combined Science Notes: Molecules

A molecule is the smallest particle of a compound formed when atoms of elements combines
The atoms combine together by forming bonds
When these bonds are formed there are energy changes
Typically heat energy […]

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The strength of Materials

By garikaib|2025-02-12T09:14:47+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Different materials have different strength. Image credit wisegeek.com ZIMSEC O Level Combined Science Notes: The strength of Materials

A beam should be made of stronger material so that it can support a greater load
Different materials have different strength
Some material is greater when put […]

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Experiment: The reaction of metals with dilute Hydrochloric acid

By garikaib|2025-02-12T09:41:04+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Copper does not react with hydrochloric acid. Image credit fphoto.com ZIMSEC O Level Combined Science Notes: Experiment: The reaction of metals with dilute Hydrochloric acid

Aim: To examine the reactivity of metals with dilute hydrochloric acid

Materials: 5 test tubes, dilute hydrochloric acid, magnesium, zinc, […]

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Experiment: Investigating the neutralisation process
Gallery
Experiment: Investigating the neutralisation process

Notes, O Level Science Notes, Ordinary Level Notes

Experiment: Investigating the neutralisation process

By garikaib|2025-02-12T09:10:28+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Experiment: Investigating the neutralisation process

Aim: To find out what happens to the pH of an acid when a base is added

Materials: vinegar, plastic beaker, measuring cylinder, stirring rod, spatula/plastic teaspoon, slaked lime (calcium hydroxide), universal indicator paper

Method

Place about 10 cm³ of vinegar in a beaker
Dilute it with an equal volume of water
Remove […]

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Purification of copper using electrolysis

By garikaib|2025-02-12T09:27:29+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Electrolysis of copper. Image credit 180daysofteaching.wordpress.com ZIMSEC O Level Combined Science Notes:Purification of copper using electrolysis

The impure copper (blister copper) yielded from the converter
Is then molded into thick sheets
These sheets become positive plates i.e.
they are connected on the positive side […]

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Electrolysis of water to produce gases

By garikaib|2025-02-12T09:41:06+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Electrolysis of water. Image credit dordt.edu ZIMSEC O Level Combined Science Notes: Electrolysis of water to produce gases

Hydrogen gas is mainly produced using electrolysis of water
In Zimbabwe this is done at the Sable Chemicals plant in Kwekwe
Water is drawn from the Sebakwe […]

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Experiment making ethanol

By garikaib|2025-02-12T09:08:16+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Fermentation of glucose ZIMSEC O Level Combined Science Notes: Experiment: making ethanol

Aim: To make ethanol by fermenting glucose

Materials: conical flask/plastic bottle, cork, glass/rubber tube,lime water, 5% glucose solution, yeast, mealie meal

Method

Add about 50cm³ of the 5% glucose solution into the flask
Add a spatula of yeast/mix mealie meal with water […]

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Lightning and safety

By garikaib|2025-02-12T09:21:25+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Lightning conductors in action. Image credit ask.com ZIMSEC O Level Combined Science Notes: Lightning and safety

Lightning has very high voltages
It can electrocute, maim or kill a person if they are struck
Several precautions can be taken to prevent this from happening:
People […]

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Experiment: Connecting solar cells to make panel

By garikaib|2025-02-12T09:38:31+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Panels are made from linked solar cells. Image credit thinksolar-us.com ZIMSEC O Level Combined Science Notes: Experiment: Connecting solar cells to make panel