Question

Please explain the observations of Activity 11.3 of NCERT science #class10.​

Answer 1

Answer:

Hey there here's a simple to understand explanation to this activity

Explanation:

To just quickly summarise the procedure ,a source of light is made to pass through a glass tank which contains sodium thiosulphate(hypo) and 1 to 2 mL of sulphuric acid.

We oberved that from three ( 2shorter sides) of the glass tank, blue coloured light is visible. However from the fourth side( the longer side that is facing the circular hole) orange and them crimson red is visible.

Okayy.. but why?

simple concept: lesser wavelength, more scattering.

We know that ( from Rayleigh's Scattering Law) that light of shorter wavelength is more strongly scattered that light having a longer wavelength.

Blue being a light having a shorter wavelength, is scattered more. So when viewed from the shorter sides of the glass tank, we see that blue colour is scattered.

Now when viewed from the longer side we see red. Red has the longest wavelength so it is least scattered.So it travels a longer distance without being scattered. So, when viewed from the longer side we see the red colour as it has traveled without being scattered while blue is already scattered at the start itself, so we don't see blue near the circular hole.