Since the number of electrons and their arrangement are responsible for the chemical behavior of atoms, the atomic number identifies the various chemical elements. Each electron is influenced by the electric fields produced by the positive nuclear charge and the other (Z – 1) negative electrons in the atom. Therefore, the number of electrons in neutral atom of Potassium is 19. The number of electrons in an electrically-neutral atom is the same as the number of protons in the nucleus.
Potassium-41 is composed of 19 protons, 22 neutrons, and 19 electrons. Very rarely (0.001% of the time) it will decay to Ar-40 by emitting a positron (β+) and a neutrino.About 89.28% of the time (10.72% is by electron capture), it decays to calcium-40 with emission of a beta particle (β−, an electron) with a maximum energy of 1.33 MeV and an antineutrino, which is an antiparticle to the neutrino.K-40 is a radioactive isotope of potassium which has a very long half-life of 1.251×109 years and undergoes both types of beta decay. Traces of K-40 are found in all potassium, and it is the most common radioisotope in the human body. Potassium-40 is composed of 19 protons, 21 neutrons, and 19 electrons. Potassium-39 is composed of 19 protons, 20 neutrons, and 19 electrons. There are 25 known isotopes of potassium, three of which occur naturally: 39K (93.3%), 40K (0.0117%), and 41K (6.7%). Mass numbers of typical isotopes of Potassium are 39 41.
Isotopes are nuclides that have the same atomic number and are therefore the same element, but differ in the number of neutrons. The difference between the neutron number and the atomic number is known as the neutron excess: D = N – Z = A – 2Z.įor stable elements, there is usually a variety of stable isotopes. Neutron number plus atomic number equals atomic mass number: N+Z=A. The total number of neutrons in the nucleus of an atom is called the neutron number of the atom and is given the symbol N. The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10-19 coulombs. Total number of protons in the nucleus is called the atomic number of the atom and is given the symbol Z. Potassium is a chemical element with atomic number 19 which means there are 19 protons in its nucleus.