Simplify the following text for a Grade 11 native English-speaking person.
Original: Atmospheric nuclear explosions are associated with mushroom clouds , although mushroom clouds can occur with large chemical explosions , and it is possible to have an air-burst nuclear explosion without these clouds .
Simplified: Atmospheric nuclear explosions are associated with mushroom clouds , although mushroom clouds can occur as a result of large chemical explosions . It is also possible to have an air-burst nuclear explosion without these clouds .