Which of the following has the smallest radius? K+ Cl- Ar Ca2+
Solution
Ionic radius follow same trend as atomic radius.
For ions in same group atomic radius increases as size increases due to increase in number of shells.
1)if same number of shells then more protons smaller(magnesium ion has less ionic radius than sodium ion and Aluminium ion (Al +3 )is smaller than magnesium(Mg +2 )
2)if same number of shells then more electrons bigger
The elements you given are isoelectonic having same electron configuration 1s 2 2s 2 2p 6 3s 2 3p 6 .They have same number of shells.(3 shells)
.
Which of the following has the smallest radius- K+ Cl- Ar Ca2+Solution.docx
1. Which of the following has the smallest radius? K+ Cl- Ar Ca2+
Solution
Ionic radius follow same trend as atomic radius.
For ions in same group atomic radius increases as size increases due to increase in number of
shells.
1)if same number of shells then more protons smaller(magnesium ion has less ionic radius than
sodium ion and Aluminium ion (Al +3
)is smaller than magnesium(Mg +2
)
2)if same number of shells then more electrons bigger
The elements you given are isoelectonic having same electron configuration 1s 2
2s 2
2p 6
3s 2
3p 6
.They have same number of shells.(3 shells)
