Question

How would you describe the structure ot an atom?

Answer 1

Up to GCSE it is a very small positive nucleus which has protons and neutrons, surrounded by negative electrons in shells or energy levels around it.

Explanation:

Protons have a charge of `+1` and a relative mass of `1`
Neutrons are neutral (have no charge) and also have a mass of `1`
Electrons are negative (have a charge of `-1`) and have a negligibly small relative mass `(1/1840)`

The first energy shell contains `2` electrons and all the ones after that contain `8`.

Beyond GCSE we learn that electrons are arranged in 4 different orbitals named `s, p, d` and `f` which contain `2, 6, 10 and 14` electrons respectively.

The "first shell", known at A-level and beyond as the "principal quantum level" has a `s` orbital (which means a maximum of `2` electrons)

The second quantum level has `s and p` (which is a maximum of `2+6` or `8` electrons), the third has `s, p and d` (which means it has a maximum capacity of `18`) and the fourth has `s, p, d and f` (which means it has a maximum electron capacity of `32`).