The typical size of atoms and small molecules is around 1 × 10-10 m (0.1 nm). For example:
|diameter of a hydrogen atom, H||1.0 × 10-10 m|
|width of a hydrogen molecule, H2||2.9 × 10-10 m|
|length of an H-H bond||0.74 × 10-10 m|
An atom consists of:
Compared to an atom as a whole:
The masses of subatomic particles are very tiny. Instead of writing their actual masses in kilograms, we often use their relative masses. The relative mass of a proton is 1, and a particle with a relative mass smaller than 1 has less mass.
Protons and electrons have opposite electrical charges.
|Subatomic particle||Relative mass||Relative charge|