21. A homonuclear diatomic molecule is one composed of two atoms of the same NO. 22. Other elements form diatomic molecules when evaporated, but these diatomic species repolymerize when cooled. 23. Other elements form diatomic molecules when evaporated, but these diatomic species repolymerize when cooled. 24. Asymmetrical diatomic molecules, e . g. 25. All of the elements in the period can form diatomic molecules except beryllium and neon. 26. Upon heating iodoform decomposes to produce diatomic iodine, hydrogen iodide gas, and carbon. 27. "' Hydrogen bromide "'is the diatomic molecule with the formula. 28. All halogens have been observed as diatomic molecules, except for astatine, which is uncertain. 29. In 1997 spectroscopic analysis revealed the dimer ( or diatomic ) absorption features of molecular oxygen. 30. Although oxygen is normally a diatomic gas, oxygen can form an allotrope known as ozone.
