Question

A strand of hair is approximately 50 μm thick. If the diameter of an atom is 1 × 10-10 m, how many atoms thick is a strand of hair?

Answer 1

Answer : The number of atoms thick in a strand of hair are
`5* 10^5\text{ atoms}`

Explanation : Given,

Diameter of an atom =
`1* 10^(-10)m`

Thickness of strand of hair =
`50\mu m=50* 10^10^(-6)m`

conversion used :
`1\mu m=10^(-6)m`

Now we have to determine the number of atoms thick in a strand of hair.

`\text{Number of atoms thick}=(50* 10^10^(-6)m)/(1* 10^(-10)m)=5* 10^5\text{ atoms}`

Therefore, the number of atoms thick in a strand of hair are
`5* 10^5\text{ atoms}`

Answer 2

Thickness of strand hair = 50 μm

Diameter of an atom =
`1 * 10^(-10) m`

Now, with the help of conversion factors, convert thickness in micrometer into meter i.e. 1 micrometer =
`10^(-6)m`

So, thickness of strand hair =50 μm= 50 \times 10^{-6} m

Therefore,

number of atoms thick is a strand of hair =
`50 * 10^(-6)m* (1 atom)/(1 * 10^(-10)m)`

=
`50* 10^(4)atoms`

Hence, number of atoms is
`50* 10^(4)atoms`thick is a strand of hair.