Krypton is a member of group 18 (noble gases) elements. A colorless, odorless, tasteless noble gas, krypton occurs in trace amounts in the atmosphere and is often used with other rare gases in fluorescent lamps.
Protons and Neutrons in Krypton
Krypton is a chemical element with atomic number 36 which means there are 36 protons in its nucleus. Total number of protons in the nucleus is called the atomic number of the atom and is given the symbol Z. The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10-19 coulombs.
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. Neutron number plus atomic number equals atomic mass number: N+Z=A. The difference between the neutron number and the atomic number is known as the neutron excess: D = N – Z = A – 2Z.
For stable elements, there is usually a variety of stable isotopes. Isotopes are nuclides that have the same atomic number and are therefore the same element, but differ in the number of neutrons. Mass numbers of typical isotopes of Krypton are 80; 82-84; 86.
Main Isotopes of Krypton
Krypton occurs in 7 natural isotopes: 78Kr, 80Kr, 81Kr, 82Kr, 83Kr, 84Kr and 86Kr. 84Kr is the most common isotope, having a natural abundance of approximately 57%. 81Kr is a trace radioisotope, decaying by electron capture with a half-life of 2.3×105 years.
Krypton-78 is composed of 36 protons, 42 neutrons, and 36 electrons.
Krypton-80 is composed of 36 protons, 44 neutrons, and 36 electrons.
Krypton-81 is composed of 36 protons, 45 neutrons, and 36 electrons.
Krypton-82 is composed of 36 protons, 46 neutrons, and 36 electrons.
Krypton-83 is composed of 36 protons, 47 neutrons, and 32 electrons.
Krypton-84 is composed of 36 protons, 48 neutrons, and 32 electrons.
Krypton-86 is composed of 36 protons, 50 neutrons, and 32 electrons.
Electrons and Electron Configuration
The number of electrons in an electrically-neutral atom is the same as the number of protons in the nucleus. Therefore, the number of electrons in neutral atom of Krypton is 36. Each electron is influenced by the electric fields produced by the positive nuclear charge and the other (Z – 1) negative electrons in the atom.
Since the number of electrons and their arrangement are responsible for the chemical behavior of atoms, the atomic number identifies the various chemical elements. The configuration of these electrons follows from the principles of quantum mechanics. The number of electrons in each element’s electron shells, particularly the outermost valence shell, is the primary factor in determining its chemical bonding behavior. In the periodic table, the elements are listed in order of increasing atomic number Z.
Electron configuration of Krypton is [Ar] 3d10 4s2 4p6.
Possible oxidation states are 0.
Most Common Application of Krypton
Krypton’s multiple emission lines make ionized krypton gas discharges appear whitish, which in turn makes krypton-based bulbs useful in photography as a white light source. Like the other noble gases, krypton is chemically highly unreactive. The rather restricted chemistry of krypton in the +2 oxidation state parallels that of the neighboring element bromine in the +1 oxidation state.
|Number of protons||36|
|Number of neutrons (typical isotopes)||80; 82-84; 86|
|Number of electrons||36|
|Electron configuration||[Ar] 3d10 4s2 4p6|
Properties of other elements