Name the scientist who first used a glass prism to obtain the spectrum of sunlight

In the dispersion of white light by a common glass prism, which one among the following is correct?

When a light beam falls on a triangular glass prism, a band of colours is obtained. Which one of the following statements is correct in this regard ?

Which one of the following colours of white light is least deviated by the glass prism?

A glass prism splits white light into different colours. This phenomenon is called dispersion of light by prism. Which one of the following statements is correct ?

The mirror used by a dentist to examine the teeth of patients is