In the periodic table, the elements are listed in order of increasing atomic number Z.Р”В®lectron configuration of PotassiumР’В is 4s1. The number of electrons in each elementРІР‚в„ўs electron shells, particularly the outermost valence shell, is the primary factor in determining its chemical bonding behavior. The configuration of these electrons follows from the principles of quantum mechanics. Since the number of electrons and their arrangement are responsible for the chemical behavior of atoms, the atomic numberР’В identifies the various chemical elements. Each electron is influenced by the electric fields produced by the positive nuclear charge and the other (Z РІР‚вЂњ 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 positronР’В (РћР†+)Р’В 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 particleР’В (РћР†РІв‚¬вЂ™, an electron) with a maximum energy of 1.33 MeV and an antineutrino, which is an antiparticleР’В to the neutrino.K-40 is a radioactive isotope of potassium which has a very long half-life of 1.251Р“вЂ”10 9Р’В 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 PotassiumР’В 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 РІР‚вЂњ Z = A РІР‚вЂњ 2Z.Р”Р‡or stable elements, there is usually a variety of stable isotopes.

NeutronР’В number plusР’В atomic numberР’В equals atomic mass number: N+Z=A. The total number of neutronsР’В in the nucleus of an atom is called the neutronР’В numberР’В 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 -19Р’В coulombs. Total number of protons in the nucleus is called the atomic numberР’В of the atom and is given the symbol Z. Oxygen is in group 6 and has 6 valence electrons.PotassiumР’В is a chemical element with atomic number 19 which means there are 19 protons in its nucleus. For example, carbon is in group 4 and has 4 valence electrons. The main group number for an element can be found from its column on the periodic table. Therefore, the number of VE is important for determining the number of bonds an atom will form, the number of unpaired electrons, and an atomРІР‚в„ўs formal charge.Р”Р‡or neutral atoms, the number of valence electrons is equal to the atomРІР‚в„ўs main group number. The valence electrons are the ones involved in forming bonds to adjacent atoms. The valence electrons (VE) are the electrons in the outer shell of an atom.

The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).

The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus.

The number of electrons in a neutral atom is equal to the number of protons.

The number of protons in the nucleus of the atom is equal to the atomic number (Z).

Generally, the number of electrons-alongside with protons and neutrons-in an atom can be determined from a set of simple rules.

I number of neutrons