Question
Question: Mass of a single atom of silver is \[1.794 \times {10^{ - 22}}\]. What is the atomic mass of silver?...
Mass of a single atom of silver is 1.794×10−22. What is the atomic mass of silver?
Solution
For this we must know the definition of atomic mass unit. We must know the number of atoms present in a certain atomic mass of an element which is given by Avogadro’s number.
Complete step by step solution:
Since we have to calculate the atomic mass of silver, let us assume that the atomic mass of silver is x grams.
Avogadro number gives us the value of the number of atoms, molecules or ions present in one mole of a given species. The value of Avogadro number or Avogadro constant is 6.022×1023. Mole is a unit to determine the amount of substance. 1 mole = 6.022 × 1023 molecules.
For example one mole of carbon atom contains 6.022×1023 carbon atoms. Similarly one mole of Na+ ion will contain 6.022×1023 number of ions.
Similarly 1 mole of silver will have 6.022×1023 moles of silver atoms. Hence
Mass of one mole of silver =mass of 6.022×1023 silver atoms. Mass of one mole of silver will be the atomic mass of silver. Hence according to this,
atomic mass of silver=mass of 6.022×1023 silver atoms.
Mass of one atom of silver is given to us that is 1.794×10−22.
mass of 6.022×1023 atoms of silver = 6.022×1023×1.794×10−22=108 atomic mass unit
Hence the atomic mass of silver is 108 u or amu.
Hence the atomic mass of silver is 108 u or amu.
Note:
As we have seen that atomic mass unit is a very small unit so instead of that we use moles as a unit. It is a unit to determine the amount of substance. 1 mole = 6.022 × 1023 molecules. Silver is a d block element and is very soft, ductile and malleable. It is extensively used in photography, catalysis and nanoparticles study.