Students who have studied biology should all know this.
Nitrogen gas is a very stable substance.
Because bonded atoms form multiple bonds, there must be one and only one σ bond, but there can be one or two π bonds.
Generally, σ bonds are formed in a "head-on" manner.
The degree of electron cloud overlap is large, making it relatively stable.
Whereas π bonds are formed in a "side-by-side" manner.
The degree of electron cloud overlap is small, making them unstable.
For example, when alkenes undergo addition reactions with Br2, it is the π bond in the carbon-carbon double bond C=C that breaks, while the σ bond does not break.
This allows only the bromine atom to be added without breaking the carbon chain.
When alkynes undergo addition with Br2, since the bond length of C≡C is shorter than that of C=C, the π bond in C≡C is somewhat firmer than in C=C, making it harder to break during addition.
Therefore the reaction rate is significantly slower than that of alkenes.
