How many particles are in 42g of CO

One mole of any element/compound has a mass equal to its gram atomic/molecular mass.

We know that Carbon has an atomic mass equal to 12g, I. E. One mole of carbon atoms weighs 12g.

We know that one mole of any substance contains 6.0225X10^23 particles(atoms, molecules, ions, etc.).

Thus 12g of Carbon contains 6.0225X10^23 atoms of Carbon. Therefore 1g Carbon will contain (6.0225X10^23)/12 atoms of Carbon.

Answer= 5.01875 X 10^22 atoms

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.