The number of carbon atoms in exactly 12 g `C^(12)` is called Avogadro's number , `N_(A) (6.022 xx 10^(23))` . One mole is the amount of material which contains Avogradro's number of particle.
These definitions emphasize that the mole refers to a fixed number of `NA^(+)` b Avogadro's number of atoms , electrons to refer to a mole of helium , a mole of electrons , or a mole of `NA^(+)` by Avogadro's number of atoms, electrons or ions respectively. On the other hand, phrases like "one mole of hydrogen" can be ambiguous , and should be restated as "one mole of hydroden atoms" or " one mole fo hydrogen molecules." But it is a matter of common practice among chemists , however , to let the name of the element stand for its mos common form. Thus one mole of `O_(2)` is frequently referred to as one mole of oxygen , whereas one moles of O is called one mole of oxygen atoms. Suppose if we take one mole molecules fo `H_(2)SO_(4)` then it contain 2 moles of H atom 1 mole of S atom and 4 moles of O atom. It can also be said that moles of oxygen molecules is `(4)/(2)` =2 mole.
According to common practise , if you have Avogadro number of hydrogen molecules, then its mass is equal to :

Options

A. 1 gm
B. 2 g
C. 4 g
D. depends on temperature

Answer

B