Which of the following has mass of 1 amu?Select answersAProtonBNeutronCHydrogen atomD α -particle

The atomic mass unit (amu) is a standard unit of mass that quantifies mass on an atomic or molecular scale.

A. Proton - A proton has a mass of approximately 1 amu.

B. Neutron - A neutron also has a mass of approximately 1 amu.

C. Hydrogen atom - A hydrogen atom has a mass of approximately 1 amu, considering it consists of one proton and one electron (the mass of the electron is negligible).

D. α -particle - An alpha particle is a helium nucleus, and it consists of 2 protons and 2 neutrons. Therefore, it has a mass of approximately 4 amu.

So, the entities with a mass of 1 amu from the given options are Proton, Neutron, and Hydrogen atom.