Questions

One fathom = 1.8288 meters = 6 feet

A fathom is a unit of length used especially for measuring the depth of water.

Colored aqueous solutions are a characteristic of transition compounds.

The only transition compound in the above choices is CrCl3.

Cr is a transition element.

The hertz (Hz) is defined as one cycle per second and is a SI unit of frequency. Here kilohertz is also a unit of frequency of waves and is defined as 1000 cycles per second. Radio waves are measured in kilohertz (KHz).

Let that something be 'x'

From the given data,

x + x/5 = 21

5x + x/5 = 21

6x = 21 x 5

=> x = 17.5

Hence, that something is x = 17.5.

National Science Day is celebrated in India on 28 February each year to mark the discovery of the Raman effect by Indian physicist Sir Chandrashekhara Venkata Raman on 28 February 1928.