Potassium was first isolated from potash, the ashes of plants, from which its name derives. In the periodic table, potassium is one of the alkali metals. All of the alkali metals have a single valence electron in the outer electron shell, which is easily removed to create an ion with a positive charge – a cation, which combines with anions to form salts. Naturally occurring potassium is composed of three isotopes, of which 40K is radioactive. Traces of 40K are found in all potassium, and it is the most common radioisotope in the human body.
Electron Affinity – Potassium
Electron affinity of Potassium is 48.4 kJ/mol.
In chemistry and atomic physics, the electron affinity of an atom or molecule is defined as:
the change in energy (in kJ/mole) of a neutral atom or molecule (in the gaseous phase) when an electron is added to the atom to form a negative ion.
X + e– → X– + energy Affinity = – ∆H
In other words, it can be expressed as the neutral atom’s likelihood of gaining an electron. Note that, ionization energies measure the tendency of a neutral atom to resist the loss of electrons. Electron affinities are more difficult to measure than ionization energies.
Electronegativity of Potassium
Electronegativity of Potassium is 0.82.
Electronegativity, symbol χ, is a chemical property that describes the tendency of an atom to attract electrons towards this atom. For this purposes, a dimensionless quantity the Pauling scale, symbol χ, is the most commonly used.
The electronegativity of Potassium is: χ = 0.82
First Ionization Energy of Potassium
First Ionization Energy of Potassium is 4.3407 eV.
Ionization energy, also called ionization potential, is the energy necessary to remove an electron from the neutral atom.
X + energy → X+ + e−
where X is any atom or molecule capable of being ionized, X+ is that atom or molecule with an electron removed (positive ion), and e− is the removed electron.
A Potassium atom, for example, requires the following ionization energy to remove the outermost electron.
K + IE → K+ + e− IE = 4.3407 eV
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 Potassium is 19. 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 Potassium is [Ar] 4s1.
Possible oxidation states are +1.
|Number of electrons||19|
|Electron configuration||[Ar] 4s1|
|Electron affinity [kJ/mol]||48.4|
|Electronegativity [Pauling scale]||0.82|
|First ionization energy [eV]||4.3407|
Properties of other elements