A gold sample contains 90% of gold and the rest copper. How many atoms of gold are present in one gram of this sample of gold?
ScienceClass 9CBSEAnswered 27 Mar 2026
Answer
Soln:
One gram of gold sample will contain 90 = =0.9g of gold
100
Number of moles of gold=mass of gold
atomic mass of gold
= 0.9
197
= 0.0046
One mole of gold contains NA atoms = 6.022×103
Therefore, 0.0046 mole of gold will contain= 0.0046 × 6.022
=2.77×1021
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