There are numerous chemicals that are used in science practical work but which only get the briefest of mentions. I thought it might be useful to make a list of some here so that you can learn what they all do. Solvents We use various solvents (to dissolve things) with water being the most obvious. …
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Category:Physics
Standard Form…
This is especially relevant to those of you doing Radley Physics Papers. Joking aside, knowing a little mathematical notation can be very helpful. Often a “back-of-the-envelope calculation” is enough to use as a guide to the sort of answer you might expect. Standard form is a way of expressing numbers as multiples of ten. It …
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Coloured Compounds….
Although I have written about chromatography, and how it can be used to separate mixtures of coloured compounds, it occurs to me that I have not really talked about why certain chemicals are a particular colour or even what colour really is. I shall try to address this omission here. Our experience of colour is …
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Balthazar…
NB – if you have posted comments, I often include follow up questions in my replies so do check back and read my responses. A standard wine bottle holds 750 ml (cm3) of liquid. That is ¾ of a litre, sometimes called 75 cl. We almost always use units derived from the litre to measure …
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It’s A Gas…
There are three common states of matter; solid, liquid and gas. This statement ignores other less common states of matter like plasma (very hot) or Bose-Einstein condensate (very cold). Exam questions often ask you to explain events in terms of the behaviour of the particles involved. This is easier if you can picture how particles …
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Diffusion…
Diffusion is the random movement of particles from areas of high concentration to areas of lower concentration. This happens because the particles in a liquid, solution or gas are able to move freely. The following video explains it quite nicely with a sugar lump dissolving in water as the example. . I will write about …
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Synchrotron…
The Large Hadron Collider is not the only particle accelerator worth talking about. In fact, there is one just 30 minutes south of us. The Diamond Synchrotron uses its electron beams to produce synchrotron light which is about 1 billion times brighter than the sun. The light is produced as synchrotron radiation (wavelengths adjustable between …
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Don’t Believe Your Lying Eyes…
Not really magic – it is science but optical illusions so magic-adjacent. I thought about this because of a question on a Winchester Election paper about strobe lighting. They are two quite long videos but I thought they were worth sharing, particularly for those who like optical illusions. They left me baffled but delighted. . .. If you …
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ROYGBIV…
White light is a mixture of electromagnetic radiation at different wavelengths. The human eye is sensitive to wavelengths between roughly 380 nanometres (nm) and 750 nm with its maximum sensitivity being at about 555 nm. Other species, such as certain insects, are sensitive to different wavelengths of light e.g. ultraviolet (a short video worth watching!) The …
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Density Of Gas…
Density means the mass of 1 cm3 of a substance. For example, 1 cm3 of water has a mass of 1 g – its density is 1 g/cm3. Lead, on the other hand is much denser than water. 1 cm3 of lead has a mass of 11.3 g ∴ lead has a density of 11.3 g/cm3. The …
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