For elements in groups one to seven, the last number in the electron arrangement is the same as what? •the total number of electrons. •the mass number. •the atomic number. • the element’s group number. respond asap

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.

that's what i got you can count the number of atoms