February 2025

Rusting and Painting

By |2025-02-12T09:39:40+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Rusting and Painting

  • Painting is a popular method used to prevent rusting
  • The structure to be painted is cleaned using an acidic solution
  • This removes existing rust and dirt
  • Sand paper/scrubbing material  is also used to clean the surface to be painted
  • The surface is then left to dry
  • Once it is dry […]
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Biogas as a source of energy

By |2025-02-12T09:06:04+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Biogas as a source of energy

  • Biogas is the gas that is obtained from fermenting manure and other organic waste
  • It is a mixture of methane, carbon dioxide and hydrogen sulphide
  • Cattle manure is commonly used as a waste to feed biogas plants
  • Small plants have been built in some parts of Zimbabwe
  • […]

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Conductors and insulators

By |2025-02-12T09:18:48+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Conductors and Insulators. Image credit sci-toys.com Conductors and Insulators. Image credit sci-toys.com ZIMSEC O Level Combined Science Notes: Conductors and insulators

  • A conductor is a material that allows electrons to move from one atom to another
  • Conductors/Conducting materials cannot be charged unless they are held using an insulating material to prevent […]
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Experiment: Demonstrating that an electric wire moves in a magnetic field

By |2025-02-12T09:01:21+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Demonstrating the motor effect. Image credit ideas-inspire.com Demonstrating the motor effect. Image credit ideas-inspire.com ZIMSEC O Level Combined Science Notes: Experiment: Demonstrating that an electric wire moves in a magnetic field

Aim:  To demostrate how a current carrying wire moves in a magnetic field

Materials: a length of flexible wire, small pieces of cardboard […]

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Methods of Joining materials

By |2025-02-12T09:16:37+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Joining parts of a plane. Image credit airportjournals.com Joining parts of a plane. Image credit airportjournals.com ZIMSEC O Level Combined Science Notes:Methods of Joining materials

  • Building structures such as bridges and pylons using solid material would be needlessly expensive
  • Most of this material would be in a neutral zone where it […]
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Arch bridges

By |2025-02-12T09:30:24+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

An arch bridge An arch bridge ZIMSEC O Level Combined Science Notes: Arch bridges

  • In an arch bridge the arch acts to support a load by converting the downward force into sideways thrust
  • Arches can make structures last longer for example old buildings and structures in European countries have lasted as […]
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Pumps: Force pump

By |2025-02-12T09:04:42+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

A solar force pump. Image credit sunfuel.co.in A solar force pump. Image credit sunfuel.co.in ZIMSEC O Level Combined Science Notes: Pumps: Force pump

  • A force pump:
  • Has a cylinder, piston, two valves and a spout (outlet)
  • It makes use of atmospheric pressure to force fluid/water into the pump through valves
  • The […]
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Substance abuse: Alcohol

By |2025-02-12T09:23:13+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Glasses of wine. Image credit pickywallpapers.com Glasses of wine. Image credit pickywallpapers.com ZIMSEC O Level Combined Science Notes: Substance Abuse: Alcohol

  • Alcohol is a legal and socially acceptable drug
  • It is however a poison
  • It is addictive and can lead to ill-health and even death
  • It is a depressant drug
  • It […]
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Injection (Depo Provera)

By |2025-02-12T09:40:01+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Image credit star.ng Image credit star.ng ZIMSEC O Level Combined Science Notes:Contraception:Injection (Depo Provera)

  • Also simply known as Depo
  • It is an injection containing medroxyprogesterone, a contraceptive injection for women that contains the hormone progestin

How it works Depo provera Depo provera injection

  • Prevents the […]
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