C Chromatic Scale as you go up: C C# D D# E F F# G G# A A# B C
C Chromatic Scale as you go down: C B Bb A Ab G Gb F E Eb D Db C
In this example we start at C and end at C, that is an octave. As you go up the scale some of the notes are sharped. As you go down, some of the notes are flatted. Notice that the sharped and flatted keys are the same keys but given different names; these are called enharmonic notes. Enharmonics sound the same but have different names. For example C# and Db is the same key. In grammar and writing, enharmonics are like homonyms; words that sound alike but have different meanings (i.e. meet, meat)
Here are several resources on chromatic scales for different instruments: