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.
What is the formula for Tin IV chromate? Sn(CrO4)2 Tin 4 means that the tin is a cation with a +4 charge. Chromate is a polyatomic ion with the formula (CrO4)-2. Since the tin ion has a +4 charge in this case, andâ¦ the chromate ion has a -2 charge, there is a 1:2 ratio of tin ions to chromate ions.