Doubt by Chinmoy Biswas

Sir, on NCERT book the flame colour of Cs (caesium) written is BLUE (wave length 455 nm).

In NCERT also written the wavelength of potassium and Rubidium are 766.5 nm and 780 nm respectively

Sir, you should be correct this.

Answers

Answer by Jay Prakash

Flame colours are dependent on temperature. As given in the NCERT book, oxidizing flame imparts the colours given in the book. So, please remember that for the NEET exam. However, on higher temperatures, different colours are produced which are helpful in corelating with the electropositive nature as described by sir in the Video.