The `C-NH_(2)` bond in acetamide is 0.1 A shorter than the `C-NH_(2)` bond in ethylamine. Way?

A) C-H bond in ethyne is shorter than C-H bonds in ethene. R) Carbon atom in ethene is sp-hybridised while it is sp^(2) in ethyne.

The C-C bond length in propene is little shorter 149 pm than the C-C bond length 154 pm in ethane. This is due to

C-=C bond length is shorter than C=C &C-C - why ?

C-=C bond length is shorter than C=C and C— C bond lengths— Why?

C - C bond length in graphite is shorter than C - C bond length in diamond - Explain.