Atomic structure - (CCEA)Compounds

Atoms have a positively-charged nucleus made of protons and neutrons, and negatively-charged electrons that orbit the nucleus in shells.

Part ofCombined ScienceStructures, trends, chemical reactions, quantitative chemistry and analysis

Compounds

A is two or more elements chemically combined.

The table below shows some common compounds. It’s useful to know that mono means one, and di means two.

  • carbon monoxide has one atom of oxygen
  • carbon dioxide has two atoms of oxygen
CompoundFormulaElements present
waterH2Ohydrogen, oxygen
carbon monoxideCOcarbon, oxygen
carbon dioxideCO2carbon, oxygen
sulfur dioxideSO2sulfur, oxygen
sulfur trioxideSO3sulfur, oxygen
nitrogen monoxideNOnitrogen, oxygen
nitrogen dioxideNO2nitrogen, oxygen
ammoniaNH3nitrogen, hydrogen
hydrochloric acidHClhydrogen, chlorine
nitric acidHNO3hydrogen, nitrogen, oxygen
sulfuric acidH2SO4hydrogen, sulfur, oxygen
Compoundwater
FormulaH2O
Elements presenthydrogen, oxygen
Compoundcarbon monoxide
FormulaCO
Elements presentcarbon, oxygen
Compoundcarbon dioxide
FormulaCO2
Elements presentcarbon, oxygen
Compoundsulfur dioxide
FormulaSO2
Elements presentsulfur, oxygen
Compoundsulfur trioxide
FormulaSO3
Elements presentsulfur, oxygen
Compoundnitrogen monoxide
FormulaNO
Elements presentnitrogen, oxygen
Compoundnitrogen dioxide
FormulaNO2
Elements presentnitrogen, oxygen
Compoundammonia
FormulaNH3
Elements presentnitrogen, hydrogen
Compoundhydrochloric acid
FormulaHCl
Elements presenthydrogen, chlorine
Compoundnitric acid
FormulaHNO3
Elements presenthydrogen, nitrogen, oxygen
Compoundsulfuric acid
FormulaH2SO4
Elements presenthydrogen, sulfur, oxygen
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