"Describe the distribution of electromagnetic radiation emitted from the sun (what wavelengths are emitted

The Sun is known to emit almost all wavelengths of electromagnetic radiation but 99% of the radiation emitted by the sun lie in the ultraviolet, visible, and infrared regions.

Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm to 400 nm (750 THz). The wavelength is shorter than that of visible light but longer than X-rays. UV rays make up about 10% of the e-m waves from the sun. UV radiation is carcinogenic to the skin, and is absorbed by the melanin pigment in the skin.

Visible light is the only e-m wave that our eyes can pick up, i.e the only e-m wave we can see. The frequency of this spectrum corresponds to a band in the vicinity of 405–790 THz. It can further be separated into different colors. It makes up a large portion of the e-m waves coming from the sun.

Infrared wave is an e-m radiation whose wavelengths longer than those of visible light. It is is generally invisible to the human eye. The wavelength of an infrared wave extend from the red edge of the visible spectrum at 700 nanometers (frequency 430 THz), to 1 millimeter (300 GHz). Most of the thermal radiation emitted by objects near room temperature is infrared. Most of the heat from the sun reach us as infrared radiation. As with all e-m radiation, infrared radiation carries radiant energy and behaves both like a wave and like a photon.

dopamine..

"it was found that some people who were taking the drug l-dopa to raise their levels of dopamine were developing schizophrenic-like symptoms supporting research a strength of the dopamine hypothesis is that there are many studies which have shown support for the neurochemical explanation."