William Prout FRS was an English chemist, physician, and natural theologian. He is remembered today mainly for what is called Prout's hypothesis.
Portrait of William Prout by Henry Wyndham Phillips
Different species of urinary calculi noted by William Prout
Prout's hypothesis, 1947
Atoms are the basic particles of the chemical elements. An atom consists of a nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms. For example, any atom that contains 11 protons is sodium, and any atom that contains 29 protons is copper. Atoms with the same number of protons but a different number of neutrons are called isotopes of the same element.
Scanning tunneling microscope image showing the individual atoms making up this gold (100) surface. The surface atoms deviate from the bulk crystal structure and arrange in columns several atoms wide with pits between them (See surface reconstruction).