B1
If something such as a bomb explodes, it bursts with noise and force, and if you explode it, you make it burst with noise and force.
Dictionary examples:
The students' laughter exploded when the teacher's pants split during a dance move. (0.0)
The chef's experimental dish exploded in the microwave, painting the kitchen with spaghetti. (0.0)
His homemade rocket exploded on the launch pad, covering him in colorful smoke. (0.0)
He put too much air in the tire and it exploded. (22.6)
A bomb exploded at one of London's busiest railway stations this morning. (56.9)