How many Hydrogen atoms are there in 5 g of NH3? (molar mass of NH3 = 17
g/mol)

5.309 × 10²⁴ atoms.

Explanation:

Given that

molar mass of NH3 = 17 g/mol

Mass of NH3 = 5g

Therefore, No of moles of NH3 = Mass/ molar mass

=  5g/ 17g/mol

= 0.294 moles.

I  mole = 6.02 × 10²³ atoms

Therefore  the number of hydrogen atoms in a 0.294 moles of ammonia  gives us

0.294× 6.02 × 10²³ × 3  ( since there are 3 hydrogens in Ammonia )

= 5.309 × 10²⁴ atoms.

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.