Lesson 2

Lesson 2:
Model of an Atom
I learnt to use the Bohr model to draw atoms. Each atom has at least one shell, which are displayed as circles surrounding the protons and neutrons. Here is the rules and regulations I follow on the number of electrons per shell.
1st shell: 2 electrons
2nd shell: 8 electrons
3rd shell: 18 electrons (8 electrons ONLY for first 20 elements)
4th shell: 32 electrons

My first sketch of a Bohr model

The farthest occupied shell from the nucleus is the valence shell. The electrons in the valence shell are the valence electrons and will be involved in chemical reactions. The model in my picture consists of 5 valence electrons. :)