Answer: molar mass
Explanation:
The molar mass of any substance is it's relative molecular mass expressed in grams. Hence, the relationship between molar mass of any substance and mass, in grams, of one mole of any substance is mathematically expressed as:
Number of moles =
(Mass in grams ➗ Molar mass)
Hence, the unit of molar mass is gram per mole (g/mol)
Thus, molar mass is the answer.
The alpha particle is the helium nucleus.
The mass of helium nucleus (⁴₂He) is 4u.
The mass of radioactive atom decreases by 4u. Look at the reaction below:
²²³₈₈Ra ---> ⁴₂He + ²¹⁹₈₆Rn
The answer would be 2 in ths case, bonding has to do with the electron orbitals.