Temporary Hard Water This is caused by calcium or magnesium hydrogen-carbonate. It can be removed by boiling the water. Ca(HCO3)2 (aqueous) …
Scum Formation
Soap contains salts such as sodium stearate and sodium palmitate and when calcium ions in hard water mix with soap, …
Hard Water
Hard water does not produce as much lather as soft water when it is used with soap and also an …
Home learning workbooks and activities
We have dug out a few home learning activity books on Amazon for you. There are plenty more out there, …
Leaf Structure
1. Waxy Cuticle – Forms a waterproof layer to stop any loss of water. 2. Upper Epidermis – Consisting of epidermal cells. These have …
Transportation in a Plant
The following diagram shows the structure inside the stem of a plant. This is how water, sugars, and minerals are …
Human Kidneys
The kidneys have an important role to play in homeostasis in humans. They filter out the urea, and excess minerals …
Human Skin
When the body is cold 1. The small capillaries near the surface of the skin constrict (vasoconstriction) so less blood …
Brain and Nervous Systems
1. Cerebrum – (consisting of the two cerebral hemispheres) A small part of the cerebrum determines what we hear. Another section interprets …
Leaching and Eutrophication
Leaching describes the “washing out” from soils any soluble chemicals that are not “bound” to the soil particles. It occurs …