Early wheels were simple wooden disks with a hole for the axle. In the early Roman empire, most horse-carts used a design featuring two chords across the wheel. The spoked wheel was invented much more recently, and allowed the construction of lighter and swifter vehicles.
Chromium(III) sulfide. Chromium(III) Sulfide is the inorganic compound with the formula Cr2S3. It is a brown-black solid. Chromium sulfides are usually nonstoichiometric compounds, with formulas ranging from CrS to Cr0.67S (corresponding to Cr2S3). Preparation.
Best Answer: You simply assign the oxidation numbers to the elements based on a few givens, like H is +1 and oxygen is -2. But, this is NOT a redox reaction and the oxidation state of chromium does not change. The oxidation state of chromium in the chromate ion is +6....................+1 +1.. x..-2 -2 -2 -2 = 0 Na2CrO4 == Na Na Cr O O O O It's like an algebra problem.We know the oxidation states for a compound must add up to zero.est Answer: You simply assign the oxidation numbers to the elements based on a few givens, like H is +1 and oxygen is -2. But, this is NOT a redox reaction and the oxidation state of chromium does not change. The oxidation state of chromium in the chromate ion is +6.