Converting Nanometers to Angstroms

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

Conversion Problem

The spectra of the element mercury have 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 canceled out. In this case, we want angstroms to 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) &Aring/nm)
wavelength in Å = (wavelength in nm) x (10 &Aring/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.