The epa limit for lead in the water supply is 15 parts per billion by mass. calculate the number of lead ions present in 1.00 kg of water that is at the epa limit for lead.

answerambulatory;

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"