January 2023

Experiment: Testing the infiltration capacity of soils

By |2022-09-15T12:40:26+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Testing infiltration in soils Testing infiltration in soils ZIMSEC O Level Combined Science Notes: Testing the infiltration capacity of soils

Materials: Tins with their tops and bottoms removed, water

Method

  1. Gently push the tins into the ground, make sure that they are in different soil types
  2. Pour 100ml of water into the cylinders and measure […]
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Isotopes and the importance of proton numbers

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

The three isotopes of hydrogen. Image credit wikipedia.org The three isotopes of hydrogen. Image credit MediaWiki ZIMSEC O Level Combined Science Notes: Isotopes and the importance of proton numbers

  • The electron orbits of these two elements is small and can only carry two electrons
  • The next element in the series is lithium
  • It comes […]
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Predicting reactions of a metal using the reactivity series

By |2022-09-15T12:39:37+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

The reactivity series. Image credit wordpress.com The reactivity series. Image credit wordpress.com ZIMSEC O Level Combined Science Notes: Experiment: Predicting reactions of a metal using the reactivity series

  • Metals do not react with water and air at the same rate
  • The rate at which they react differs from metal to metal
  • Some metals […]
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Neutralisation/Salts

By |2022-09-15T12:39:28+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes: Neutralisation/Salts

  • The acidity and alkalinity of a solution can be represented on the pH scale
  • If the pH is low i.e less than 7 then the solution is acidic
  • If the pH is high i.e higher than 7 then the solution is alkaline
  • If a solution has a pH of 7 […]
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Extraction of copper from sulphides

By |2022-09-15T12:39:20+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

ZIMSEC O Level Combined Science Notes:Extraction of copper from sulphides

  • Copper is extracted from various types of ore including sulphide ores
  • For example copper ores found on the Great Dyke near Mhangura is of the sulphide type
  • Once the sulphide ore is extracted from the earth
  • It is crushed to form a very fine powder which is then further […]
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Liquification of air

By |2022-09-15T12:39:08+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Sable chemicals plant. Image credit zimeye.net Sable chemicals plant. Image credit zimeye.net ZIMSEC O Level Combined Science Notes: Liquification of air

  • In Zimbabwe the air liquification plant is at Sable Chemicals
  • Two main components of air are separated:
  • Nitrogen and Oxygen
  • These two gases are used in either liquid or gas form
  • […]

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Ethanol as a source of energy

By |2022-09-15T12:38:57+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

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

  • Ethanol is also known as alcohol
  • It is made by fermenting plants with a high sugar content
  • Sugar cane is commonly used to make ethanol in Zimbabwe
  • The plant is grown in Zimbabwe’s Lowveld
  • Water from Mutirikwe and Bangala Dams is used to irrigate the crop
  • Biomas is […]
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Science:Lighting

By |2022-09-15T12:38:49+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Lightining is a result of electrostatic discharge. Image credit zmescience.com Lightining is a result of electrostatic discharge. Image credit zmescience.com ZIMSEC O Level Combined Science Notes: Conductors and insulators

  • Clouds are poor conductors because they are made of mostly water particles
  • They may become charged due to friction forces within them […]
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Photovoltaic cells/Solar Panels

By |2022-09-15T12:38:41+02:00January 24th, 2023|Notes, O Level Science Notes, Ordinary Level Notes|

Solar Panels. Image credit  digitaltrends.com Solar Panels. Image credit digitaltrends.com ZIMSEC O Level Combined Science Notes: Photo-voltaic cells/Solar Panels

  • Solar cells convert radiation from the sun into electrical energy
  • These cells are mad from silicon
  • Which is a semiconducting material
  • While most metals are good conductors of electricity because they […]
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