Ques: The strength of bonds by 2s-2s , 2p-2p , 2p-2s overlap has order

(1) s-s>s-p>p-p

(2) p-p >s-p >s-s

Explain with reason ?

@ diksha 
acc to the question , option no 1 that is s-s>s-p>p-p turns out to be the correct answer . 
as u knows s-s is head on head overlapping and hence , its the strongest . and the 2^nd strongest is s-p due to intermixing of overlapping .. 
and the least strong is p-p due to axial overlapping .. 
HOPE IT CLEARS YOUR DOUBT 
IF ANY MORE , THEN LET ME KNOW 
ALL THE BEST ..
 

The extent of overlapping depends on principl quantum number ,,,1s-1s,will show much extent than 2p_2p,which show much than 2s_2p

It depends if we talk about size then s-s is smaller in size hence the distance of nucleus is small from electron hence s-s bond is stronger than s-p and p-p 

If we talk about direction then p-p overlapping is directional and s-s overlapping is non directional si p-p overlapping is strong 

 

One more factor that is area p orbital have more area than s orbital hence there will be extent overlapping so p-p overlapping is strong

 

It depend on the extent of overlapping as p-p has more extent of overlapping.It doesnot has any affect of IND(internuclear distance ) imfact all pp ss and sp have same IND.