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Why, in a thermal flask, does having a vacuum layer help keep the coffee warm?

Heat is transferred by 3 processes, conducation, convection and radiation. Having a vacuum layer stops heat being transferred away from the coffee by conduction. Conduction works by air molecules bumping int...
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Answered by Benjamin O. • Physics tutor
3688 Views

Explain the role of the diaphragm when breathing in and out

The diaphragm is a large muscle located at the base of the lungs. It is naturally dome shaped when relaxed. When we need to inhale, the diaphragm will contract and flatten out. This increases the volume of t...
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Answered by Salko K. • Biology tutor
6535 Views

Explain why an atom has no overall charge

Atoms are made up of three different types of particle. Protons and neutrons exist in the nucleus, while electrons orbit. The relative charges of these particles mean that protons are positive while electron...
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Answered by Salko K. • Chemistry tutor
8851 Views

How do you form phenylamine from benzene? Include reagents and conditions and the name of the reactions

Benzene to nitrobenzene / nitration of benzene. Conditions: concentrated nitric acid and concentrated sulfuric acid. Carried below 50 o C to avoid further substitution of nitro groups Nitrobenzene to phenyla...
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Answered by Denzell O. • Chemistry tutor
11558 Views

What is the "Subjunctive"? And when should it be used?

The subjunctive is what's known as a "mood", which merely means that it's used in a different way to "normal" (indicative) verbs. That is, in most cases, to express an element of doubt. H...
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Answered by Alexander H. • Latin tutor
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