When I was taught energy levels in a hydrogen atom – I was given the formula ;Energy = -13.6/n^2.
(1)What purpose does that minus sign signify?
(2)If energy in the first Bohr orbit is -13.6 and in the second one is -3.4 is:
(a) The energy in the second orbit greater as
-3.4 > -13.6 or
(b) The energy in the first orbit is greater as
|-13. 6| > |-3.4|?
Is there a better way to look at the energy values (as the minus sign is confusing)?
In: 12
The energy of an electron is more a measure of the potential energy of the attraction between positive nucleus and negative electron. For attractive forces, the further away something, the more PE it will have (like gravity). Therefore, outer orbits have more energy than lower orbits.
But what is the maximum energy? If PE increases with distance, then an electron infinitely far from the nucleus would have maximum energy.
However, we also know that attractive forces diminish over distance. An infinitely far electron does not exert much attraction on the nucleus (and vice versa). So we say an infinitely far electron has zero potential energy.
Using this *zero energy reference point*, we can consider an electron approaching the nucleus. Recall that the closer the electron is, the less PE it will have. If the maximum energy is zero, and it only decreases, then the energy of an electron can only be negative.
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