Basics of Hydrocarbon Chemistry. Crude oil is a mixture of hydrocarbon molecules, which are organic compounds of carbon and hydrogen atoms that may include from one to 60 carbon atoms. The properties of hydrocarbons depend on the number and arrangement of the carbon and hydrogen atoms in the molecules.
Why does my download stop before it is finished? When a user experiences an issue while downloading files, it is usually a problem with the connection to their Internet service.
While you're downloading music you've purchased from iTunes, occasionally something could go wrong that interrupts the download. Maybe your computer freezes or the power goes out, shutting off your computer off. The good news is that you haven't lost these incomplete downloads forever.