Uses of isotopes:
In agriculture,
C-14 is used to trace the path of photosynthesis.
In medicine,
Iodine -131 is used in the treatment of
goiter
Initially, weigh the correct amount of 
calculated from the formula.
Number of moles =
As 1 mole of is given and molar mass of is 
, then
1 mole of = 
Mass of in g = 
Thus,
1 mole of = 58.44 g.
Now, the weighed amount of i.e. 58.44 g is added to a 1 liter container and then add small amount of water in the container to dissolve the salt. After that, fill the container with distilled water to the graduation mark or until the total volume reaches 1 liter.
Thus, option (c) is correct i.e. first put one mole of salt in the container then add the water with stirring till the total volume reaches 1 liter.
There is no hydrogen in ammonium sulfide it is just 1 ammonium and 1 sulfer
Answer:
petroleum,natural gas,lime stone, coal,water,acetylene etc.
