why are nuclear bombs more hazardous than conventional bombs?

Nuclear bombs are more hazardous than conventional bombs because -

1) Nuclear bombs with a small yield are significantly more powerful than the largest conventional explosives and a single weapon is capable of destroying an entire city

2) There is also a risk of accidental exposure to harmful radiation from several nuclear reactors that are used to generate power

3) Theft of nuclear materials can enable the creation of crude bombs known as "dirty bombs" which can be used by anti - social elements and terrorist groups.

HOPE THIS HELPS :)