The chromatic scale is based upon a sequence of semitones only and this includes every possible note within one octave. Here is the C chromatic scale.
The same scale could be written out using flats, however it is more common to do this when descending, as such;
Because each chromatic scale contains every possible note within one octave, once you have learned one you have basically learned them all. As an example, the A chromatic scale (written next) contains exactly the same notes as the C chromatic scale, the only difference between them being the note upon which they begin. This starting note, in all scales, is referred to as the tonic or key note.