Question

The diameter of a hydrogen atom is 212pm. Find the length in kilometers of a row of 6.02×1023 hydrogen atoms.

Answer 1

Diameter of a single hydrogen atom = 212 pm

Calculating the length of a row of
`6.02*10^(23)` Hydrogen atoms:

`6.02*10^(23)` Hydrogen atoms *
`(212pm)/(1 H atom)`

=
`1.276 * 10^(26) pm`

Converting the length from pm to km:

The conversion factor for converting pm to m is
`1 m = 10^(12)pm`

The conversion factor from m to km is
`1 km = 10^(3)m`

`1.276 * 10^(26) pm` *
`(1 m)/(10^(12)pm )`*
`(1 km)/(1000 m)` =
`1.276 * 10^(11) km`

Therefore,
`1.276 * 10^(11) km` is the distance in kilometers when
`6.02*10^(23)` Hydrogen atoms are placed in a row.