Find
the total mass of protons in 34 mg of `NH_(3)` at STP.

Find the total mass of 'neutrons in 7 mg of ""^(14)C.

What is the ratio by mass of N and H in NH_3

Find the number of proton & electron in Al3+ ion ?

Be^(3+) and a proton are accelerated by the same potential, their de - Broglie wavelengths have the ratio ( assume mass of proton = mass of neutron ) :

Find the oxidation number of cobalt in K[Co(CO)_3 NH_3]

A mixture of Ne and Ar kept in a closed vessel at 250 K has a total K.E.=3 kJ. The total mass of Ne and Ar is 30 g. Find mass % of Ne in gaseous mixture at 250 K.

Determine the de-Broglie wavelength of a proton, whose kinetic energy is equal to the rest mass energy of an electron. Given that the mass of an electron is 9.1 xx 10^(-31) kg and the mass of a proton is 1,837 times as that of the electron.