Inorganic, organic and biochemistry

An atom consists of a very small positively charged nucleus, surrounded by negative electrons held by electrostatic attraction. The motion of electrons changes when chemical bonds are formed, nuclei being unaltered.

Nucleus:   positive charge

Electron:   negative charge

Electrostatic attractive force:  Electrons are attracted to Nucleus.

Electrostatic repulsion force:  among  the protons.

From planetary model to quantum theory