Question

What do you mean by the invisible spectrum? How will you investigate the existence of radiation beyond the red violet ends of the spectrum?

Answer 1

We can detect the range of spectrum other than the visible region by passing through silver chloride solution. The spectrum beyond violet and beyond red which is not visible to the human eye. The visible range of spectrum can be defined as the range of wavelength from about 380nm to 750 nm. The spectrum beyond violet is called infrared radiation and spectrum beyond red is called infrared radiation.

Complete step-by-step solution: -
The visible spectrum can be defined as the range of spectrum beyond the red and violet end of the visible spectrum. But the invisible spectrum cannot be seen through our eyes since it is not in the range of wavelength that humans can see. This range of invisible spectrum produces radiation which has a strong heating effect but it is not visible to us. The spectrum of radiation is more chemically active beyond violet and hence it is called ultraviolet radiation. The radiation beyond red produces strong heat effects; these radiations are called infrared radiations.

Note: When the visible spectrum or the range of wavelength from red to violet are passed through silver chloride solution the solution remains unaffected and there is no colour change in the colour of spectrum. But beyond the two extreme ends of violet and red the violet finally becomes dark brown. The spectrum beyond violet is called infrared radiation and spectrum beyond red is called infrared radiation.