January 2023

Molecules

By |2022-09-15T12:40:17+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Molecules of carbon, oxygen, hydrogen and water 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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Population distribution

By |2022-09-15T12:40:08+02:00January 24th, 2023|Notes, O Level Geography, Ordinary Level Notes|

World population distribution. Image credit MediaWiki World population distribution. Image credit MediaWiki ZIMSEC O Level Geography Notes: Population:Population distribution

  • Population distribution is the spread of people over an area, country or region
  • In the past population distribution was mainly influenced by natural factors such as soil fertility and the environment
  • Whilst natural factors […]
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Reasons why Zimbabwe was colonised

By |2022-09-15T12:39:57+02:00January 24th, 2023|Notes, O Level History Notes, Ordinary Level Notes|

Cecil John Rhodes. Image credit MediaWiki Cecil John Rhodes. Image credit MediaWiki ZIMSEC O Level History Notes: The Colonisation of Zimbabwe:Reasons why Zimbabwe was colonized

  • There were several reasons why Zimbabwe was turned into a colony by the BSAC
  • Some these reasons include:
  • In order for Cecil John Rhodes to fulfill his Cape […]
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Deficiency Diseases

By |2022-09-15T12:39:49+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Iodised salt can prevent iodine deficiency Iodised salt can prevent iodine deficiency ZIMSEC O Level Combined Science Notes: Deficiency Diseases

  • A person might suffer from a deficiency disease if their diet lacks certain essential minerals and vitamins
  • Two essential minerals and vitamins are:
  • Iodine and
  • Vitamins

Iodine Goitre is a [...]
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The reactions of metals and water

By |2022-09-15T12:39:40+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: The reactions of metals and water

  • Water is a compound of oxygen and hydrogen
  • When metals react with water they remove the oxygen from the water
  • We say the metals displace the hydrogen from the water
  • A metal oxide is formed
  • Freeing up the oxygen
  • The following word equation summarizes the nature of […]
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Experiment: The corrosion of metals by acids

By |2022-09-15T12:39:31+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Experiment: The corrosion of metals by acids

Aim: Investigating the corrosion of some metals by acids

The corrosion of metals by acid gives off hydrogen gas The corrosion of metals by acid gives off hydrogen gas

Materials: 5 test tubes, dilute hydrochloric acid, granulated zinc, iron fillings/iron nail, copper foil, […]

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Experiment: Nickel plating a piece of copper sheet

By |2022-09-15T12:39:12+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Nickel plating copper Nickel plating copper ZIMSEC O Level Combined Science Notes:  Experiment: Nickel platting a piece of copper sheet

Aim: To nickel plate a piece of copper

Materials: beaker, nickel sulphate, boric acid, burner, nickel electrode, 1.5 v cell, copper electrode/copper plated item, universal indicator

Method

  1. In a beaker make 20cm3 a solution using 54g […]
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Experiment: Burning fuels

By |2022-09-15T12:39:00+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Burning Fuels Burning Fuels ZIMSEC O Level Combined Science Notes: Experiment: Burning fuels

Aim: To burn and investigate the nature of fuels

Materials: methylated spirits/alcohol, candle, meths burner, bunsen burner, paraffin, tin lid or porcelain dish, tongs

Method

  1. Light a meths burner and observe the flame
  2. Burn a small amount of alcohol on a tine lid, […]
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