Question

The diameter of a neutral helium atom is about 1 x 10^2 pm. Suppose that we could line up helium atoms side by side in contact with one another. Approximately how many atoms would it take to make the distance 1 in from end to end?

Answer 1

`2.539* 10^(8)` helium atoms will be needed to cover 1 inch distance.

Step-by-step explanation:

Diameter of helium atom =
`1* 10^2 pm`

`1 pm=10^(-12) m`

1 m = 39.3701 inch

Then in
`10^(-12) m=10^(-12)* 39.3701 inch`

`1 pm=10^(-12)* 39.3701 inch`

Diameter of helium atom in inches =
`10^2* 10^(-12)* 39.3701 inch`

Let the number of helium atoms required to cover 1 inch distance be x.

Total distance = 1 inch

`x* 10^2* 10^(-12)* 39.3701 inch=1 inch`

`x=(1 inch)/(10^2* 10^(-12)* 39.3701 inch)`

`x=2.539* 10^(8)` helium atoms

`2.539* 10^(8)` helium atoms will be needed to cover 1 inch distance.