A Model Beryllium Atom

Here is an example using element number 4, beryllium (Be). We will use a mass number of 9. Consider each point above in order:

The atomic number (Z) is 4, so protons (p+) = 4 and electrons (e-) = 4.
Beryllium is in period 2, so the number of energy levels occupied = 2.
Of the 4 electrons (4e-), 2 will go in the 1st. energy level (maximum allowed), leaving 2 to go in the 2nd. energy level.
The group number is 2, so 2 electrons will go in the highest used energy level (valence level). This is redundant, we already figured this out above!
If the mass number (A) is 9, then with 4 protons we need 5 neutrons (n^o) to account for this.

Bohr model for a beryllium atom.

Bohr model for a beryllium atom without labels.

Pencil sketchof a Bohr model of a beryllium atom.

Can you see a problem with the beryllium model atom when no labels are used? Click here to find out.

An atom has an atomic number of 24, and an atomic mass of 52. Name and give the numbers of each type of subatomic particle found in this atom?