February 2025

Asexual reproduction

By |2025-02-12T09:34:33+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

A bud on a sugarcane cutting. Image credit 10degreesabove.com A bud on a sugarcane cutting. Image credit 10degreesabove.com ZIMSEC O Level Combined Science Notes: Reproduction in plants: Asexual reproduction/ Vegetative reproduction  

  • Is also known as asexual reproduction
  • This takes place when plants reproduce without producing seeds
  • Such plants have modified stems, roots or […]
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Variation

By |2025-02-12T08:59:05+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Variation in chillies. Image credit chilipapryczka.pl Variation in chillies. Image credit chilipapryczka.pl ZIMSEC O Level Combined Science Notes: Variation

  • The living world has many thousands of different types of plants and animals
  • For example lions are different from hyenas which in turn are different from say goats
  • In plants the Msasa trees are […]
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Experiment: to show that solids change shape when they melt

By |2025-02-12T09:11:07+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Melting wax takes up the shape of the container. Image credit about.com Melting wax takes up the shape of the container. Image credit about.com ZIMSEC O Level Combined Science Notes: An  experiment to show that solids change shape when they melt

Materials: tin lid/evapouration dish, burner, burner stand, candle wax

Method

  1. place […]
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Properties of Nonmetals vs metals

By |2025-02-12T09:21:43+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Common metal objects. Image credit blogspot.com Common metal objects. Image credit blogspot.com ZIMSEC O Level Combined Science Notes: Experiment: Properties of Metals and Non-Metals

  • Elements can be divided into two groups:
  • Metals and Non-metals
  • Examples of metals are: copper, zinc, iron, gold, silver, chrome, lead and tin
  • Almost all metals have certain properties that makes them […]
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Experiment: The reaction of metals with dilute Hydrochloric acid

By |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 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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Neutralisation/Salts

By |2025-02-12T09:10:01+02:00February 12th, 2025|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 |2025-02-12T09:26:36+02:00February 12th, 2025|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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