10th9thacidallotropesatomatomicbasebondscarbonchapchapterchemicalclasscompoundscorrosionequationsexplainationformulafullganguehydrocarbonsimportantindicatorsintromassmattermetalsmodelmoleculesphysicalpropertiespurereactionssaltssaturatedseriessolutiontemperaturetypesunsaturatedvalency