How many neutrons are in a nucleus of a hydrogen - 1 atom?

A. 0

B. 1

C. 2

D. impossible to tell without additional information

How many neutrons are in a nucleus of a hydrogen - 1 atom?

B. 1

B. 1 - Hydrogren-1 can only mean there is 1 neutron. It's obvious there is 1 proton or else it wouldn't be hydrogen, so they wouldn't put a number after it unless they were indicating the number of neutrons