Mottles in subsoil color within a soil profile is usually caused by the A Soil structure

B Depth of plowing

C Oxidation state of iron

D Organic matter content

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.