February 2025

Purification of copper using electrolysis

By |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 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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Experiment making ethanol

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

Fermentation of glucose 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

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

By |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 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 |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 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

Aim:  Connecting solar cells to make a solar panel

Materials: 3 or more solar cells, connecting leads, a voltmeter and an […]

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Experiment:Making a model electric motor

By |2025-02-12T09:03:40+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

An electric motor. Image credit jeffryerickson.com An electric motor. Image credit jeffryerickson.com ZIMSEC O Level Combined Science Notes: Experiment:Making a model electric motor

Aim:  To make a model electric motor

Materials: copper wires, switch, coil (made from varnished copper), magnet, paper clips, rechargeable battery

Method

  1. Set up the coil and magnet as shown in the […]
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Experiment: Testing the strength of various joints

By |2025-02-12T09:18:29+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Welding joints. Image credit youtube.com Welding joints. Image credit youtube.com ZIMSEC O Level Combined Science Notes:Experiment: Testing the strength of various joints

Aim: To test the strength of various joints in beams

Materials:  pieces of metal,poplar wood, glue, drawing pins/nails, bolts and nuts, old plastic rulers, burner, bricks/clamp, welding equipment/burner

Method Testing [...] </p srcset=

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Dams

By |2025-02-12T09:33:42+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

An arch shaped dam wall. Image credit MediaWiki An arch shaped dam wall. Image credit MediaWiki ZIMSEC O Level Combined Science Notes: Dams

  • Dams usually fail due to lack of stability rather than lack of strength
  • The sideways thrust of dammed water can topple the wall
  • This thrust varies from when […]
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Introduction to diseases

By |2025-02-12T09:25:32+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Parirenyatwa entrance. Image credit financialgazette.co.zw Parirenyatwa entrance. Image credit financialgazette.co.zw ZIMSEC O Level Combined Science Notes: Introduction to diseases

  • A disease is an illness
  • Diseases are caused by pathogens
  • Pathogens come in the form of:
  • bacteria, viruses, fungi, protozoa(single celled animals) and small worms
  • Bacteria can be viewed using a light microscope

    • […]

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