Àdàpọ̀ kẹ́míkà jẹ́ is a pure ohun kẹ́míkà ògidì kan tó ní ẹ́límẹ̀ntì kẹ́míkà méjì tàbí jùbẹ́ẹ̀lọ ọ̀tọ̀ọ̀tọ̀ tó ṣe é yàsọ́tọ̀ sí ohun míràn pẹ̀lú ìdarapọ̀ kẹ́míkà. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together in a defined spatial arrangement by chemical bonds. Chemical compounds can be molecular compounds held together by covalent bonds, salts held together by ionic bonds, intermetallic compounds held together by metallic bonds, or complexes held together by coordinate covalent bonds. Pure chemical elements are not considered chemical compounds, even if they consist of molecules that contain only multiple atoms of a single element (such as H2, S8, etc.), which are called diatomic molecules or polyatomic molecules. Brown, Theodore L.; LeMay, H. Eugene; Bursten, Bruce E.; Murphy, Catherine J.; Woodward, Patrick (2009), Chemistry: The Central Science, AP Edition (11th ed.), Upper Saddle River, NJ: Prentice Hall, pp.