Number of moles is defined as the ratio of given mass in g to the molar mass.
The mathematical formula is:
Number of moles = 
(1)
Number of zinc atoms is equal to 
, by Avogadro number, number of moles can be calculated.
As, 1 mol=
atoms, hence,
= 0.2822 mol
Now, from formula (1), calculate mass in g (molar mass of zinc = 65.4 g/mol)
0.2822 mol = 
mass in g = 
= 18.45588 g
Thus, by rounding off the above number, it will come near about 19 g approximately.
Hence, option (C) is the correct answer.
1) Ca-37, with a half-life of 181.1(10) ms.
Atoms of the same element but with different atomic masses are called isotopes. They possess a different atomic mass, due to the indifferent number of neutrons that the atoms of a given element have.
Answer:
Two reagents that can be used to distinguish between ethane and ethyne are Tollens' reagent and ammoniacal CuCl solution.
