A chromatic scale is made up of semitones - on the piano, play all the keys in sequence.
Fingering is maybe the simplest of all scales:
- 3 on all black keys
- 1 on all white keys, except:
- 2 on 2nd white key of a pair
(eg: going up with right hand: 1 on E, 2 on F, 3 on F#, etc
Read more: Wikipedia