The atomicity of K2Cr2O7 is I. 9 II. 11 III. 10 IV. 12
The number of atoms in the molecules of an element is known as its atomicity. In the case of K2Cr2O7, there are 2 atoms of potassium(K), atoms of chromium(Cr) and 7 atoms of oxygen (O). So the atomicity of this compound is the sum of all the atoms present in this compound i.e 2+2+7=11. Option B.
