Test:200 QNo:4

Q4 The strength of bonds formed by 2s-2s, 2p-2p and 2p-2s overlap has the order
a) s-s<s-p<p-p
b) s-s>s-p>p-p
c) s-p<s-s<p-p
d) p-p<s-s<s-p
Your Answer: (a)
Correct Answer: (b)
Score: -1
Explaination :
s-s strength is highest & p-p has lowest

nature of sigma bond bond strength

s-s 1.0

s-p 1.73

p-p 3.0
(reference: http://www.citycollegiate.com/bond_theoryXIa.htm)

(The relative strength of a sigma bond is related to the extent of overlap of the atomic orbitals. This is known as the 'principle of maximum overlap'.
Due to spherical charge distribution in s-orbital, generally s-s overlapping is not so effective as s-p and p-p overlapping.
Where p-orbitals have directional charge distribution and longer lobes which cause more effective overlapping. Thus s-s sigma bond is relatively weak.)

which is harder to break \sigma or \pi

it is pi bond which is p-p overlap
hence p-p overlap is WEAKER than s-s

u compared all as sigma bonds it is not mentioned in Q to assume so
taking p-p bond as pi bonds gives b as the correct one

but its not mentioned to assume pi bonding as well ...