Question

The pair of elements having approximately equal ionisation potential is

Solution

Correct option is

Al, Ga

 

Ionisation energy increases with decreases in atomic size and decrease in shielding effect.  

Al(13) = 1s2, 2s2, 2p6, 3s2, 3p1   

Ga(31) = 1s2, 2s2, 2p6, 3s2, 3p6, 4d10, 4s2, 4p1  

As the atomic electronic configuration show there are ten d-electrons in Ga which shield the nuclear charge less effectively than s and p electrons. Hence, the outer electron is held fairly strongly by the nucleus. Consequently ionisation energy slightly increases inspite of the increase in atomic size from Al to Ga. Hence, Al and Ga have approximately equal ionisation potential.   

SIMILAR QUESTIONS

Q1

Which of the following transition involves maximum amount of energy?

Q2

 

The formation of the oxide ion O2–(g) requires first an exothermic and then an endothermic step as shown below  

               

                    

This is because 

Q3

The electronic configuration of four elements are given below. Which element does not belong to the same family?

Q4

The least stable ion among the following is

Q5

Ist and IInd IE of Mg are 7.646 and 15.035 eV respectively. The amount of energy needed to convert all the atoms of magnesium into Mg2+ ions present in 12 mg of magnesium vapours is [Given, 1 eV = 96.5 kJ mol–1]

Q6

Which of the following is the most electropositive element?

Q7

Which of the following sequence correctly represents the decreasing acidic nature of oxides?

Q8

Which of the following pairs of species have nearly same size?

Q9

The set representing the correct order of ionic radius is

Q10

Which is not the correct order for the stated property?