What is the chemical difference between acids and bases?

The chemical differences between acids and bases are: ionization and redox reaction.

Explanation:

Ionization: acids are substances that form hydrogne ion,  as the only positively charged ion when in solution; whereas bases produce hydroxonium ion, when dissociated in water. This directly affects the pH of the substances: Acids are 0-6.9 whereas alkalis are 8-14.Reduction and oxidation (redox): reaction: acids are generally proton donors or electron pair recipient whereas a base is a proton recipient or electron pair donors.

No. an alpha particle is a pair of protons and a pair of neutrons, i.e. a helium