Calculate the percentage of nitrogen in `NH_3` (Atomic mass of N = 14, H = 1amu)

Calculate the mass percentage of oxygen in CaCO_3 .

Naturally occuring boron has two isotopes of masses 10 amu and 11 amu. Calculate the percentage of each isotope if the average atomic mass of boron is 10.2 .

Calculate the mass % of oxygen in Fe_(3)O_(4)

Calculate the number of molecules In 90g of water. (Hint -Atomic mass H=1, 0=16)

NH_3 , gas at STP is kept in a cylinder of volume 5600mL. a) How many moles of NH_3 , is present in the cylinder? b) Calculate the mass of gas in the cyclinder. c) Find the number of molecules in the gas calculate the number of atoms in it. (Hint: Atomic mass, N=14, H-D)

How many GAMs are present in each the samples given below? Calculate the number of atoms present in each of the sample ? (Atomic mass N= 14,0=16). 42g Nitrogen.

How many GAMs are present in each the samples given below? Calculate thenum-berof atomspresentin eachof thesample ? (Atomic mass N= 14,0=16). 42g Nitrogen. 80g Oxygen,

Calculate the volume of 34 g of 'NH_3' at STP?