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.
Formula Chemical Name Chemical Name Chemical Formula LiNO 3 Lithium Chlorate Ag 2 SO 4 Silver Nitrite KNO 2 Iron (II) Chlorite Fe 2 (SO 3) 3 Potassium Nitrate Be(IO) 2 Iron (III) Hypochlorite MnSO 4 Zinc Carbonate NaIO 2 Lead (II) Perchlorate Ni 2 (SO 3) 3 Beryllium Sulfite Mg(IO 3) 2 Nickel (III) Iodate Hg 3 (PO 4) 2 Magnesium Sulfate Ca(BrO) 2 Lead (IV) Periodate Pb 3 (PO 4) 4 Calcium Phosphite Ba(BrO 2