Atom bombardment ejects what appeared to be hydrogen nuclei. By 1920 he had accepted that the hydrogen nucleus is a distinct particle within the atom and named it proton. Neutrons have no electrical charge and have a free mass of 1,839 times the mass of the electron, or , the heaviest of the three constituent particles, but it can be reduced by the nuclear binding energy. Neutrons and protons (collectively known as nucleons) have comparable dimensions—on the order of —although the 'surface' of these particles is not sharply defined. The neutron was discovered in 1932 by the English physicist James Chadwick.
Atom (time) Atom (time) An Atom of time or "a-tom" (“indivisible” in Greek), refers to the smallest possible unit of time. One of the earliest occurrences of the word “atom” to mean the smallest possible unit of measuring time is found in the Greek text of the New Testament in Paul's . The text compares the length of time of the “atom” to the time needed for “the twinkling of an eye.” The text reads: “en atomo, en repe ophthamou” – the word "atom" is usually translated "a moment" - “In a moment, in the twinkling of an eye”. With that meaning