To determine which diatomic molecule contains a double bond, we need to examine the bonding characteristics of the given diatomic molecules: [tex]\( N_2 \)[/tex], [tex]\( O_2 \)[/tex], [tex]\( Cl_2 \)[/tex], and [tex]\( Br_2 \)[/tex].
1. Nitrogen ([tex]\( N_2 \)[/tex]):
Nitrogen forms a molecule with a triple bond between the two nitrogen atoms. The nitrogen-nitrogen bond is quite strong due to the triple bond.
2. Oxygen ([tex]\( O_2 \)[/tex]):
Oxygen forms a molecule with a double bond between the two oxygen atoms. The bond order for [tex]\( O_2 \)[/tex] is 2, indicating a double bond.
3. Chlorine ([tex]\( Cl_2 \)[/tex]):
Chlorine forms a molecule with a single bond between the two chlorine atoms. This is typical for halogens forming diatomic molecules.
4. Bromine ([tex]\( Br_2 \)[/tex]):
Bromine also forms a molecule with a single bond between the two bromine atoms. Like chlorine, this is expected as bromine is also a halogen.
Given this information, the diatomic molecule containing a double bond is [tex]\( O_2 \)[/tex].