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.
Sulfur trioxide (alternative spelling, sul ph ur trioxide) is the chemical compound with the formula SO 3.In the gaseous form, this species is a significant pollutant, being the primary agent in acid rain. It is prepared on massive scales as a precursor to sulfuric acid.n terms of electron-counting formalism, the sulfur atom has an oxidation state of +6 and a formal charge of +3. The Lewis structure consists of an S=O double bond and two SâO dative bonds without utilizing d-orbitals. The electrical dipole moment of gaseous sulfur trioxide is zero.