( ) are organic compounds that are chemically based on carbon, hydrogen and other nonmetallic elements.
举一反三
- Of the more common elements(元素) are hydrogen, oxygen, carbon, iron, copper, etc.
- All organic compounds contain the element A: Phosphorus B: Nitrogen C: Sulfur D: Carbon E: Oxgen
- Which elements is not one of the three most common ones in a plant? A: Carbon B: Hydrogen C: Oxygen D: Sulfur
- Compounds composed of molecules (molecular compounds) usually contain only elements.
- All minerals are compounds of various elements.