The answer is K⁺ < K < K⁻.
- The radius of cation is smaller than its atomic radius.
Cation is formed by losing electrons. When electrons are less, the attraction towards the remaining electrons by the nucleus is larger than the attraction in neutral atom. As well as, the repulsions between electrons are less. Hence, the radius of cation is smaller than its atomic radius.
- The radius of anion is larger than its atomic radius.
Anion is formed by gaining electrons. When more electrons are present, the attraction towards the electrons by the nucleus is smaller than the attraction in neutral atom. As well as, the repulsions between electrons are high due to the higher number of electrons. Hence, the radius of anion is larger than its atomic radius.
The increasing order of the radius of the given species is [tex]\boxed{{{\text{K}}^ - } < {\text{K}} < {{\text{K}}^ + }}[/tex].
Further Explanation:
Ions are the species that are formed either due to the loss or gain of electrons.
A neutral atom, when accepts an electron, gets converted into negatively charged species, known as an anion. The number of electrons becomes more than the number of protons in the atom. As anion has more number of electrons, there occurs strong electrostatic repulsions between these electrons and are pushed away from each other. Therefore the radius or size of anion is larger than that of the neutral parent atom.
The formation of anion occurs as follows:
[tex]{\text{X}}\left( {{\text{Neutral atom}}} \right) + {e^ - } \to {{\text{X}}^ - }\left( {{\text{Anion}}} \right)[/tex]
A neutral atom, when loses an electron, gets converted into positively charged species, known as a cation. The number of electrons becomes less than the number of protons in the atom. This results in an increase in the effective nuclear charge and thereby increasing attractions between the nucleus of the atom and the electrons. Therefore the size of cation is smaller than that of the parent atom.
The formation of cation occurs as follows:
[tex]{\text{X}}\left( {{\text{Neutral atom}}} \right) - {e^ - } \to {{\text{X}}^ + }\left( {{\text{Cation}}} \right)[/tex]
[tex]{{\text{K}}^-}[/tex] is an anion of potassium atom while [tex]{{\text{K}}^ + }[/tex] is a cation of potassium atom. As we know, the radius of anion is always larger than the parent atom while that of cation is smaller than the radius of the parent atom. So [tex]{{\text{K}}^ - }[/tex] is the largest and [tex]{{\text{K}}^ + }[/tex] is the smallest.
Therefore the increasing order of the radius of the given species is as follows:
[tex]{{\text{K}}^-}<{\text{K}}<{{\text{K}}^+}[/tex]
Learn more:
1. Which ion was formed by providing the second ionization energy? https://brainly.com/question/1398705
2. Write a chemical equation representing the first ionization energy for lithium: https://brainly.com/question/5880605
Answer details:
Grade: High School
Subject: Chemistry
Chapter: Periodic classification of elements
Keywords: atom, ion, species, order, electrons, anion, cation, K-, K+, K, potassium, effective nuclear charge, larger, smaller, neutral atom, negatively charged species, positively charged species.
