Periodic TableHard
Question
The first ionisation potential of Na, Mg, Al and Si are in the ordrer :
Options
A.Na > Mg < Al < Si
B.Na > Mg > Al > Si
C.Na < Mg < Al > Si
D.Na > Mg > Al < Si
Solution
Writing their E.C.
Na = ls2, 2s2, 2p6, 3s1
Mg = ls2, 2p2, 2p6, 3s2
Al = ls2, 2p2, 2p6, 3s2, 3p1
Si = ls2,2p2, 2p6, 3s2, 3p2
On the basis of ENC, the I E1 must increases from Na to Si because all these belongs to same period. Due to higher ENC and completely filled s-subshell, I. E1 (Na). Although ENC for Al must be greater than ENC for Mg, but in Al electron is released from 3p while in Mg it goes from 3s. Because 3s is closer to nucleas than 3p and in Mg, s-subshell is completely filled also so I. E1 (Mg) > I. E1 (Al). I. E1 (Si) > I. E1 (Al) due higher ENC thus correct order is :
Na < Mg > Al < Si
Na = ls2, 2s2, 2p6, 3s1
Mg = ls2, 2p2, 2p6, 3s2
Al = ls2, 2p2, 2p6, 3s2, 3p1
Si = ls2,2p2, 2p6, 3s2, 3p2
On the basis of ENC, the I E1 must increases from Na to Si because all these belongs to same period. Due to higher ENC and completely filled s-subshell, I. E1 (Na). Although ENC for Al must be greater than ENC for Mg, but in Al electron is released from 3p while in Mg it goes from 3s. Because 3s is closer to nucleas than 3p and in Mg, s-subshell is completely filled also so I. E1 (Mg) > I. E1 (Al). I. E1 (Si) > I. E1 (Al) due higher ENC thus correct order is :
Na < Mg > Al < Si
Create a free account to view solution
View Solution FreeMore Periodic Table Questions
The electrongativity of the following elements increases in the order :...Which of the following does not have hemiacetal group :-...An element has electronic configuration [Xe] 4f7 5d1 6s2. It belong to the.....block of the periodic table....The first ionisation potential of Na is 5.1 eV. The value of electron gain enthalpy of Na+ will be :-...Which one the following ions has the highest value of ionic radius?...