Question

what is spectrum ? how its formed ?weite one example from nature?

Answer 1

An emission spectrum is the line pattern formed when an element is excited and gives off energy. An absorption spectrum is formed when white light passes through a cool gas. The gas absorbs certain wavelengths of energy and allows others to pass through.
An example of a spectrumis a group of activities used for teaching someone how to play basketball. Spectrum is the range of colors of wavelength energy sent out from a light source when viewed through a prism. An example of aspectrum is a rainbow.

Answer 2

spectrum is the band of 7 colours
it is formed from the 7 colours of sunlight.
violet colour is having shorter wave length and red colour is having longer wave length.