yes the are all the same
They don't. Sulphur has about twice the atomic mass of oxygen.
They don't contain the same number of particles because some particles are more dense than others making one atom and another atom the same mass but not have the same number of particles.
Atomic mass ratio for O : N is 15.9994  : 14.0067 .So it takes 14.0067/15.9994 moles of Oxygen to have the same mass as one mole of nitrogen. This is valuated at 0.8754516 to 1.00000
an oxygen and a hydrogen atom do not weight the same
yes.
Because the mass of carbon is not the same as that of oxygen.
No all oxygen atoms do not have the same mass as you can get isotypes of the same element which are still called the same except that they can have more or less neutrons than the standard model this is why the weight is refered to as an average mass
Carbon and oxygen or two different elements, with different masses.
Both nitrogen and oxygen exist at standard temperature and pressure as diatomic molecules. Therefore, the relative masses of equal numbers of molecules of the substance will the same as the ratios of their atomic masses, which are 15.9994 for oxygen and 14.0067 for nitrogen. The mass of oxygen that contains the same number of molecules as 42 g of nitrogen is 42(15.9994/14.0067) or 48 g, to the justified number of significant digits.
NO They are not the same.
To determine the mass of oxygen gas containing the same number of moles as 56 grams of sulfur, calculate the molar mass of sulfur (32 g/mol) and use it to find the number of moles in 56 grams. Then, since the molar ratio of sulfur to oxygen in a compound is 1:1, this same number of moles of oxygen gas would weigh 32 grams.
Both nitrogen and oxygen exist at standard temperature and pressure as diatomic molecules. Therefore, the relative masses of equal numbers of molecules of the substance will the same as the ratios of their atomic masses, which are 15.9994 for oxygen and 14.0067 for nitrogen. The mass of oxygen that contains the same number of molecules as 42 g of nitrogen is 42(15.9994/14.0067) or 48 g, to the justified number of significant digits.