How can uv light be used to diagnosis some species of microsporum?

To detect some species of microsporum, the UV light from the wood lamp will be used to check the area of suspected infection. The lamp will be placed about 10 to 30 cm away from the skin. If there is fluorescence or if the light is reflected back, that means that microsporium is present. 

1) noble gases2) by increasing atomic number3) noble gases