Some Basic Concepts of Chemistry / रसायन की कुछ मूलभूत अवधारणाएँ
JEE Main & Advanced
Chemistry
Some Basic Concepts of Chemistry / रसायन की कुछ मूलभूत अवधारणाएँ
Question Bank
Mock Test - Some Basic Concepts of Chemistry
question_answer
Given that the abundance of isotopes \[^{54}Fe\], \[^{56}Fe\] and \[^{57}Fe\] is 5%, 90% and 5%, respectively. The atomic mass of Fe is
A)55.85
B)55.95
C)55.75
D)55.05
Correct Answer:
B
Solution :
The atomic mass of iron is \[=\frac{(5\times 54)+(90\times 56)+(5\times 57)}{100}=55.95\]