Find
the total mass of protons, in 34 mg of `NH_3` at STP.

Find the total number of neutrons and Find the total mass of neutrons, in 7 mg of C^14 (Assume that mass of a neutron = 1.675 xx 10^-7 kg )

Find the total number of protons of NH_3 at STP

Find the value of frac(cos56^@)(sin34^@)

Assertion: An electron and proton enters a magnetic field with equal velocities, then, the force experienced by the proton will be more than electron. The mass of proton is 1837 times more than electron.

Find the odd one out: Reaction of NH_3 with HCl, reaction of Mg with O_2 reaction of CaO with water, reaction of Mg with CuSO_4 solution

The mass of a H- atom is less than the sum of the masses of a proton and electron. why is this?

The masses of two bodies are measured to be 15.7 +- 0.2 kg and 27.3 +- 0.3 kg. What is the total mass of the two and error in it.