Is mg a metal non metal or noble gas

Why is an elements atomic mass not listed as a whole number on the periodic table

The agent of mechanical weathering in which rock is worn away by the grinding action of other rock particles is call

What is the wavelength of a 3*10^12 hz infrared wave a 3*10^20m b 1* 10^4m c 3*10^-3m d 1*10^-4 m