Witness the exciting reactions that occur when alkali metals come into contact with other substances. What does this tell us about their properties? Chemistry - Periodic Table - Learning Points. The alkali metals make up Group 1 of the...

Huntington's is a genetic disease, which usually occurs in middle age. There is a genetic test for Huntington's but, with no cure available, would you choose to be tested if you were at risk? Biology - Cells And DNA - Learning Points. A...

Electrolysis is fundamental to industrial processes. How was it discovered, how does it work and what are its uses? Chemistry - Reactions - Learning Points. The Chemist Humphry Davy developed the reaction we now call electrolysis....

Scientists have found a way to make it rain. But weather modification has its critics, and there may be unforeseen consequences surrounding the "cloud seeding" process. Earth Science - Weather - Learning Points. When silver iodide is...

We look at the effects of osmosis on the volume of potato and the appearance of red onion cells. Two cylinders of potato are measured and weighed before one is placed in salt water and the other in fresh water. We can see how osmosis...

We use a supersaturated solution of sodium ethanoate to demonstrate instant crystallisation. Sodium ethanoate is added to water and is then heated to allow all of the crystals to dissolve. When it is cooled it forms a supersaturated...

We examine the number of microorganisms in different types of milk using resazurin indicator. Samples of pasteurised milk, UHT milk and powdered milk are left in the open for three days before resazurin indicator is added and the samples...

We use filtration and evaporation to separate out a mixture of water, sand and salt. The sand is removed using filtration, as it did not dissolve in the water. The remaining solution is heated until the water evaporates, leaving behind...

We compare the properties of three iron mixtures: iron and water, iron and oil and a ferrofluid - a mixture of compounds containing iron and oil. First, we look at how iron filings behave when mixed with water and then oil. We then hold...

We extract the DNA from a kiwi fruit by mashing it with detergent liquid, salt and water. The mixture is then filtered and incubated before a layer of chilled ethanol is added. The jelly-like DNA can then be extracted. Biology - Cells...

We use the enzyme pepsin and hydrochloric acid to simulate the conditions within the stomach in two boiling tubes. Cooked egg whites are ground and added to two boiling tubes of hydrochloric acid, but one is mixed with a crushed antacid...

We use yeast to let us observe anaerobic respiration. The yeast is added to warm water and glucose. A layer of oil is placed over the solution so that no oxygen is available. The solution starts to bubble and the gas produced passes...

We extract copper metal from copper chloride solution using electrolysis. The electric current causes copper to form at one electrode and chlorine gas to form at the other. The presence of chlorine is tested using blue litmus paper....

We demonstrate denaturing by adding the enzyme trypsin to photographic film. Strips of photographic film are added to trypsin solution at different temperatures to determine the optimum conditions for the enzyme. In the right conditions...

We look at how chemical filtration can be used to remove contaminants from water. Potassium permanganate is used as the contaminant. First, we try to remove it using physical filtration, with filter paper and a funnel. This does not...

We use potassium ferricyanide and luminol indicator to show how forensic scientists detect blood at crime scenes. The luminol indicator contains luminol, sodium hydroxide and hydrogen peroxide. When luminol comes into contact with the...

We use three chemical solutions to create an oscillating reaction. The three different solutions are mixed using a magnetic stirrer and the colour changes from clear to amber to dark blue. This pattern repeats as the concentrations of...

We use a drinking straw, some water and universal indicator to show that breathing out creates acid. Universal indicator is added to the water to show its pH value. When we blow into the water the indicator changes colour showing that...

We use mercury(II) chloride solution and potassium iodide to demonstrate a precipitation reaction. Saturated potassium iodide solution is placed on a magnetic stirrer and the speed is set so that a vortex is created. Mercury(II) chloride...

We separate the ions in copper dichromate gel using electrolysis. We see the positive blue copper ions move to the negative electrode and the negative yellow chromate ions move to the positive electrode. Chemistry - Reactions - Learning...

We demonstrate a displacement reaction using silver nitrate and copper. A tree-shaped piece of copper is submerged in silver nitrate solution. The silver ions displace the copper and the tree slowly becomes coated with silver metal. At...

Meanders and oxbow lakes are found in the middle course of a river. Discover how a meander forms and how this process can lead to an oxbow lake. Earth Science - Geology - Learning Points. At its middle course, a river gathers water...

This amateur mathematician proposed an exciting theorem that stood unproved for over three centuries. He claimed he had the proof – but no room to write it in the margin of his book. Maths - History Of Maths A Twig Math Film. Reinforce...

Salt is found in the oceans and Earth's surface. How do we collect this salt and separate it from the materials it is mixed with? Chemistry - Atoms And Bonding - Learning Points. Salt is found in oceans, lakes and underground rock beds....