February 2025

Introduction and importance of population studies

By |2025-02-12T08:56:31+02:00February 12th, 2025|Notes, O Level Geography, Ordinary Level Notes|

A child holding a clinic card. Image credit BBC A child holding a clinic card. Image credit BBC ZIMSEC O Level Geography Notes: Population:Introduction and importance of population studies

  • Population studies is the scientific study of human populations
  • It entails the study of:
  1. population numbers
  2. Their growth and decline
  3. deaths
  4. births
  5. […]

Comments Off on Introduction and importance of population studies

Reproduction in Plants:Development after fertilization

By |2025-02-12T09:29:14+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

A flower fertilisation. Image credit studyblue.com Fertilisation of a flower. Image credit studyblue.com ZIMSEC O Level Combined Science Notes: Reproduction in plants: Reproduction in Plants:Development after fertilization

  • Once the ovules inside the ovary have been fertilized a lot of changes takes place
  • The fertilized ovules develop into seeds inside the ovary
  • The ovary […]
Comments Off on Reproduction in Plants:Development after fertilization

Experiment: Testing the alkalinity/acidity of the soil

By |2025-02-12T09:45:43+02:00February 12th, 2025|Notes, O Level Science Notes, Ordinary Level Notes|

Testing the PH of soil. Image credit blogspot.com Testing the PH of soil. Image credit blogspot.com ZIMSEC O Level Combined Science Notes: Testing the alkalinity/acidity of the soil

Materials: Universal indicator/PH paper/PH Test meter, distilled water, test tubes, soil samples

Method

  1. Place the soil samples into test tubes to a height of about […]
Comments Off on Experiment: Testing the alkalinity/acidity of the soil

Molecules

By |2025-02-12T09:07:27+02:00February 12th, 2025|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 […]
Comments Off on Molecules

Population distribution

By |2025-02-12T09:22:10+02:00February 12th, 2025|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 […]
Comments Off on Population distribution

Reasons why Zimbabwe was colonised

By |2025-02-12T08:56:00+02:00February 12th, 2025|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 […]
Comments Off on Reasons why Zimbabwe was colonised

Deficiency Diseases

By |2025-02-12T09:16:24+02:00February 12th, 2025|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 [...]
</p srcset=

Comments Off on Deficiency Diseases

The reactions of metals and water

By |2025-02-12T09:34:49+02:00February 12th, 2025|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 […]
Comments Off on The reactions of metals and water

Experiment: The corrosion of metals by acids

By |2025-02-12T09:02:23+02:00February 12th, 2025|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, […]

Comments Off on Experiment: The corrosion of metals by acids
Go to Top