Thickness of strand hair = 50 μm
Diameter of an atom =
Now, with the help of conversion factors, convert thickness in micrometer into meter i.e. 1 micrometer =
So, thickness of strand hair =50 μm= 50 \times 10^{-6} m
Therefore,
number of atoms thick is a strand of hair =
=
Hence, number of atoms is thick is a strand of hair.
Answer:
c. 3
Explanation:
The unbalanced reaction expression is given as:
Fe + O₂ → Fe₂O₃
To balance the expression gives the coefficient of oxygen.
Assign the coefficients a,b, c and use a mathematical approach to solve this problem:
aFe + bO₂ → cFe₂O₃
Conserving Fe: a = 2c
O: 2b = 3c
Now let c = 1, a = 2, b =
Multiply through by 2,
a = 4, b = 3 and c = 2
4Fe + 3O₂ → 2Fe₂O₃
The coefficient of O₂ is 3