What is the moon's atmosphere composed of?

To construct your own detailed breakdown of the composition of the moon's atmosphere,

list any number of gases, compounds, or other substances you choose. Then, next to

each item on your list, write "Zero percent".

The moon has no atmosphere.

The Earth's Moon has no atmosphere. Its mass is too small to produce a gravitational field capable of retaining gaseous atoms or molecules.

The moon does not have an atmosphere as is generally understood but gases such as radon and helium have been detected on the moon in very very small quantities. They usually escape the moons gravity fairly quickly and so cannot build up to form a permanent atmosphere.
To construct your own detailed breakdown of the composition of the moon's atmosphere,

list any number of gases, compounds, or other substances you choose. Then, next to

each item on your list, write "Zero percent".

The moon has no atmosphere.