What is the oxidation state of chromium in Na2Cr2O7?

 Na = +1 and O = -2 Na2Cr2O7 There are 2 atoms of Na, so 2 (+1) = +2 and there are 7 atoms of O, so 7 (-2) = -14 +2 -14 = -12 The net charge has to be 0, but we have -12. What added to -12 will equal 0? That would be +12. There are 2 Cr atoms, so +12/2 = +6, and that is the charge of Cr. Check to see if you are right: +2 -14 +12 = 0. Yay! So the charge of Cr is +6.

oxidation state +6 ...........................................

Cr = +6                       ......................................................................................................                                                                                                                                          

the oxidation number of Cr in sodium dichromate is 6+

Chromium has oxidation state of +6

I don't know it am try to know it onw