The heat-trapping nature of and other gases was demonstrated in the mid-19th century.

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

Match with o for organic and i for inorganic for each compound

The double bond between a carbon atom and two oxygen atoms (a molecule of carbon dioxide) has two characteristics. what are they? a.an ionic bond is formed between the oxygen and carbon atoms. b.four valence electrons are shared. c.two valence electrons are shared. d.valence electrons are shared between oxygen atoms.