Converting Nanometers to Angstroms

This example problem demonstrates how to convert nanometers to angstroms. Nanometers (nm) and angrstroms (Å) are both linear measurements used to express extremely small distances.

Problem:

The spectra of the element mercury has a bright green line with a wavelength of 546.047 nm. What is the wavelength of this light in angstroms?

Solution:

1 nm = 10^-9 m
1 Å = 10^-10 m

Set up the conversion so the desired unit will be cancelled out. In this case, we want angstroms to the the remaining unit.

wavelength in Å = (wavelength in nm) x (1 Å/10^-10 m) x (10^-9 m/1 nm)
wavelength in Å = (wavelength in nm) x (10^-9/10^-10) Å/nm)
wavelength in Å = (wavelength in nm) x (10 Å/nm)
wavelength in Å = (546.047 x 10) Å
wavelength in Å = 5460.47 Å

Answer:

The green line in mercury's spectra has a wavelength of 5460.47 Å

It may be easier to remember there are 10 angstroms in 1 nanometer. This would mean a conversion from nanometers to angstroms would mean moving the decimal place one place to the right.