Answer :
(200 divided by mass number) x Avogadro’s number
200 divided by 126.90 = 1.576
1.576 x 6.02 x 10^23 = 9.48752×1023
200 divided by 126.90 = 1.576
1.576 x 6.02 x 10^23 = 9.48752×1023