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What's the distance from a nucleus to an electron? © Getty Images

What's the distance from a nucleus to an electron?

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The Bohr radius, is the estimated distance between protons in the nucleus and electrons - but electrons aren't solid, stationary particles...

Asked by: Alan Dunne, Ireland


The simple answer would be about one-twentieth of a nanometre. But this would only be reasonable if the electron were a solid particle.

Quantum mechanics tells us that we can only speak of an electron's orbital position in a statistical sense. We talk about the electron's 'wave function', which gives us a measure of that probability, which has a value arbitrarily close to the nucleus, and also on the other side of the galaxy. The maths work, even though we can't picture what it is working on.

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