The document discusses the basic subatomic particles that make up atoms: protons are positively charged particles found in the nucleus with a mass of 1.672 x 10−24 grams, neutrons are neutral particles found in the nucleus with a mass of 1.675 x 10−24 grams, and electrons are negatively charged particles found outside the nucleus with a mass of 9.109 x 10−28 grams.