Ions of an element of group 1 participate in the transmission of nerve signals and transport of sugars and aminoacids into cells. This element imparts yellow colour to the flame in flame test and forms an oxide and a peroxide with oxygen. Identify the element and write chemical reaction to show the formation of its peroxide. Why does the element impart colour to the flame?
Sodium ions participate in transfer of nerve signals, regulating the flow of water across cell membranes and in the transport of sugars and amino acids into cells. Sodium imparts a golden yellow colour to the flame in a flame test. This happens because the heat from the flame excites the outermost orbital electron to a higher energy level. When the excited electron comes back to the ground state, there is emission of radiation in the visible region of the spectrum, and for sodium is yellow at 589.2 λ/nm.
The reaction of sodium with oxygen to form sodium peroxide is given as
2Na + O2→ Na2O2 (peroxide)
The stability of the sodium peroxide is due to the stabilisation of large anion O22- by larger cation Na+.