gases facts Selected as the most interesting among chemistry related questions in Chemistry quiz What is inside Swiss cheese holes?Carbon dioxide is produced by bacteria feeding on the lactic acid. In the Middle Ages, the holes were considered a sign of imperfection and cheese makers would try to avoid them.Created by: Kasiacheese facts » Are gas fittings tightened clockwise or anti-clockwise?It depends on the gas. Some gas fittings use reverse threads to prevent disastrous misconnections. For example, oxygen fittings are right-handed, but acetylene and other flammable gases use left-handed fittings.Created by: globalquiz.orgtechnology facts » Which gas is colorless and odorless?Methane is the main component of natural gas piped into homes for domestic heating and cooking purposes. In order to assist in detecting leaks, a sulphur-like odorant is added the gas used by consumers.Created by: Kasiachemistry facts » Which of the following is not a chemical element?Methane. Neon, chlorine and nitrogen are chemical elements. Methane is a chemical compound, the simplest alkane and the main component of natural gas.Created by: globalquiz.orgchemical elements facts » What is the chemical symbol of helium?He. H is the chemical symbol of hydrogen. Hg is the chemical symbol of Mercury.Created by: globalquiz.orgchemistry facts » Play chemistry quiz and see all the questions.