Direct a beam of light from a torch or a laser beam on the test tubes. Is the path of the light beam visible in the liquid?

IF the solution is diluted, can the path of light be visible?

Is the beam of light scattered by particles in a solution?

A small metal plate (work function W) is kept at a distance d from a singly ionized, fixed ion. A monochromatic light beam is incident on the metal plate and photoelectrons re emitted. Find the maximum wavelength of the light beam so that some of the photoelectrons may go round the ion along a circle.