The pH scale
Universal indicator results showing the pH of various solutions. Image credit MediaWiki ZIMSEC O Level Combined Science Notes: The pH scale
The pH colour chart. Image […]
February 2025
Steel making
Steel beams. Image credit risleysteelservices.ca ZIMSEC O Level Combined Science Notes: Steel making
- The iron from the oxygen lance process is poured into a ladle and
- Small amounts of other metals are mixed with it
- It is mixed with metals such as:
- manganese, cobalt, chromium […]
Summary of plating and its uses
Tin plating is used in making food cans. Image credit alsagerfoodbank.org.uk ZIMSEC O Level Combined Science Notes: Summary of plating and its uses
- The electroplating processes can be summarized as below
- The various plating processes and their uses […]
Experiment:Making coke and collecting the resulting gases
Making coke ZIMSEC O Level Combined Science Notes: Experiment:Making coke and collecting the resulting gases
Aim: To make coke using coal and collect the gas and liquid by-products
Materials: crushed coal, test tubes, glass tubing, splints, lead ethanoate solution, filter paper, red and blue litmus paper, sodium hydroxide solution, beaker, water, trough, […]
Experiment: Charges between charged bodies
Like charges repel and unlike attract ZIMSEC O Level Combined Science Notes: Experiment: Charges between charged bodies
Aim: To demonstrate the forces of static electricity
Materials: glass/perspective rod, 2 polythene rods, silk cloth, woolen cloth and 2 watch-glasses
Method
- Balance two watch-glasses so that the top one is sitting on […]
Experiment: To measure the potential difference of a simple cell
Testing simple cell electrodes ZIMSEC O Level Combined Science Notes: Experiment: To measure the potential difference of a simple cell
Aim: To measure the potential difference of a simple cell when different electrodes are used
Materials: dilute sulphuric acid, voltmeter, beaker, leads and crocodile clips, magnesium ribbon,lead foil, copper foil, […]
Electric motors
A simple motor. Image credit youtube.com ZIMSEC O Level Combined Science Notes: Electric motors
- An electric motor converts electrical energy into kinetic energy
- This is caused by the interaction of the electrical field of the coil and
- The magnetic field of the magnets in the […]
Experiment: Comparing roof truss structures
A bridge made of ice cream sticks. Image credit pinterest.com ZIMSEC O Level Combined Science Notes:Experiment: Comparing roof truss structures
Aim: To determine which structure is best for roof trusses/bridge girders
Materials: Poplar wood /ice cream sticks/grass straws, stikistuff/drawing pins/glue, tin of sand, […]
Pier Bridge
A pier bridge. Image credit sehinc.com ZIMSEC O Level Combined Science Notes: Pier Bridge
- A simple bridge is also known as a span bridge
- It is made up of reinforced concrete and
- it spans across the gap
- It’s maximum possible span (length which it transverses)
[…]
Pumps: Lift pump
ZIMSEC O Level Combined Science Notes: Pumps: Lift pump
- It has a cylinder
- A piston
- Two valves and
- a spout
- They make use of atmospheric pressure which forces fluid (water) into the pump through valves
- Valves allow fluid to only flow in one direction
- At any given point there is one valve open and another closed
