A radioactive metal atom decays by emitting an alpha particle, which is a helium nucleus. The
alpha particles are collected as helium gas. A sample of helium with a volume of 12.05 mL was
obtained at 765 mmHg and 23 °C. How many atoms decayed during the period of the
experiment?

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.

i would say b

explanation:

but i think i would need more information than that