Potassium is the metal here and it has an Oxidation number of +1 in every compound because all Alkali Earth metals have an Oxidation Number of +1.
(The other elements: Oxygen -2 and Chromium (Cr) +6)
For the formula you have given whicch may be a test or it may be wrong!
+3. K is +1, O is -2 so as the total of the oxidation numbers in a neutral compound is zero Cr must be +3
0 = 2 + 6 -8
K2CrO4 potassium chromate Cr is +6
K2Cr2O7 potassium dichromate Cr is +6
+1. K is a group 1 metal (alkali metal) and all of these almost invariably have an oxidation state of +1 in their compounds.
+6 for each Cr
-2 for each O
Chromium is in oxidation state VI (+6).
+6 for Cr
+6 for Cr
potassium dichromate is K2Cr2O7. The oxidation number of Cr is -6. (Oxygen is -2, K is +1 so Cr must be -6)
+6
Potassium dichroamte is K2Cr2O7, in the dichroamte ion both Cr atoms have an oxidation number of +6.
+6. 07 gives -14. K2 gives +2. As the molecule is neutral Cr2 must give +12. As there are 2 atoms 1 Cr must give +6.
+6 for Cr
potassium dichromate is K2Cr2O7. The oxidation number of Cr is -6. (Oxygen is -2, K is +1 so Cr must be -6)
+6
Potassium dichroamte is K2Cr2O7, in the dichroamte ion both Cr atoms have an oxidation number of +6.
+6. 07 gives -14. K2 gives +2. As the molecule is neutral Cr2 must give +12. As there are 2 atoms 1 Cr must give +6.
In this kind of compound, oxygen is conventionally assigned an oxidation number of -2 and potassium an oxidation number of +1. For electrical neutrality, chromium must have an oxidation number of + 6, because 2(+1) + 2(+6) + 7(-2) is zero.
+2 for Ca, +6 for Cr, -2 for each O
In CrBr (chromium monobromide) Cr would have an oxidation number of +1. This compound is not known perhaps you meant CrBr3, where chromium has an oxidation number of +3
Cr is a transition metal and has a variation of oxidation number from 0 in the elemental state to +6 in the dichromate ion.
In Cr2O72- chromium (Cr) has an oxidation number of 6+ while oxygen has an oxidation number of 2-.
As with any other element, the oxidation number of Cr depends on whether and how it is chemically bonded. The oxidation number of pure elements is arbitrarily defined to be 0. In compounds, Cr has oxidation numbers of +2, +3, and +6, depending on the compound.
+6