One of the many isotopes used in cancer treatment is 79198Au, with a half-life of 2.70 d. Determine the mass of this isotope that is required to give an activity of 285 Ci.

sup bro, im dumb, but this is what i found xd

"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"