Identify the incorrect statement(s). (P) The central metal atom shows +VI oxidation state in potassium chromate and potassium dichromate. (Q) Limonite and willemenite are ores of zinc. (R) Zinc oxide is called as white lead and used as a whitening material.

P. The central metal atom in potassium chromate and potassium dichromate is Cr. Chromium has +VI oxidation state in K₂CrO₄ and K₂Cr₂O₇. Q. Limonite (Fe₂O₃.3H₂O) is an ore of iron and willemite is an ore of zinc. R. Zinc oxide is an inorganic compound with the formula ZnO. ZnO is a white powder that is insoluble in water, and it is widely used as an additive in numerous materials and products including rubbers, plastics, ceramics, glass, cement, etc. White lead (PbCO₃).2Pb(OH)₂ is a complex chemical compound containing both a carbonate and a hydroxide portion and occurs naturally as a mineral for lead. White lead compounds were used as pigmenting materials like cement, lubricants, etc. but due to its toxicity, it is not used frequently.  Hence, both the statements Q and R are incorrect.