Achemical equation is shown: na + h2o → naoh + h2 according to the law of conservation of mass, how many atoms of hydrogen exist in the products of this reaction? 2 3 4 6

4

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

Thus in the reactants, there are 4 atoms of hydrogen , 2 atoms of oxygen and 2 atoms of sodium.Thus there will be 4 atoms of hydrogen, 2 atoms of oxygen and 2 atoms of sodium in the product as well.

Thus there will be 4 atoms of hydrogen exist in the products of this reaction.

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.