What is elements of first transition series?

• The elements from scandium(Z=21) to zinc (Z=30) constitute the first transition series.  In the first element, scandium, the 3d subshell starts filling up.  Its electronic configuration is 1s22s2p63s2p6d14s2.
  
• For reasons of space, we shall describe configurations of outer shells only, leaving aside the configuration up to 3p level (argon configuration) which remains the same throughout the period.
• The outer electronic configuration of scandium may, thus, be written as 3d14s2.
• The titanium (Z=22) has one more d electron added to it.  Its outer electronic configuration is 3d24s2.
• This procedure continues and the d orbitals get filled up more and more, step by step, on moveing towards the right along this period.
• the outer electronic configurations of other elements are vanadium(Z=23), chromium (Z=24),manganese (Z=25), iron(Z=26), cobalt(Z=27), nickel(Z=28), copper(Z=29), zinc(Z=30).