A radioactive isotope has a half-life of 45 minutes. How long would it take for a sample of this isotope to decay to the point where only 10% of the original amount is still there

water is used to store them because it would keep the radiation from getting out in the open and causing harm to the workers

the ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (uvr) from the sun, protecting life on earth from its potentially harmful effects. when the sky is clear, there is an inverse relationship between stratospheric ozone and solar uvr measured at the earth's surface.