Respuesta :
Answer:
The smallest ion is : Mg 2+
Increasing Order of size :
Mg2+ < Na+ < F- < O2-
Explanation:
Isoelectronic Species : Species having same number of electrons .
[tex]Z_{eff}[/tex] = Effective attraction of the nucleus felt by the outer shell electrons.
The size of the atom is decided by :
- Its atomic number (number of proton)
- the effective nuclear charge.
As the positive charge increases the size of the ion decreases.
As the negative charge increases the size of ion also increases.
Negative charged ions : F- , O2-
Negative charge are formed when electrons are added to the atoms.
When Negative ion is formed :
- Number of proton remain same
- Number of electron get increased
Hence it becomes difficult for the proton in the nucleus to attract the electrons.
Electron - electron Repulsion increases
[tex]Z_{eff}[/tex] = decreases
Size increase
Positive charged ions : Na+ , Mg2+
Positive charge are formed when electrons are removed from the atoms.
When Positive ion is formed :
- Number of proton remain same
- Number of electron get reduced
Hence more attraction of the nucleus is felt by the outer electron.
Electron - electron Repulsion Decreased
[tex]Z_{eff}[/tex] = increases
Size decreases
