A. Smaller electronegativity of alkali metals
B. Smaller ionic radius of these metals
C. De-excitation of electrons from higher energy levels to low energy level
D. Excitation of electrons from low energy levels to higher energy levels
¨ Alkali and alkaline earth metals impart colors when heated over a burner due to the excitation of electrons from low energy levels to higher energy levels.
¨ Alkali metals and alkaline earth metals are highly reactive metals that readily lose electrons to form cations. When these metals are heated in a flame, the energy from the flame can excite electrons in the metal atoms, causing them to move from lower energy levels to higher energy levels.
¨ As the excited electrons return to their original energy levels, they release the excess energy in the form of light. This light appears as a characteristic color, which depends on the energy difference between the excited and ground state of the electrons.
¨ The colors observed when alkali and alkaline earth metals are heated over a burner are due to the emission of light by the excited electrons. For example, when sodium is heated, it emits a yellow-orange color, while potassium emits a violet color.
Submitted by :- Jamil Ahmed