The diagram above shows a potassium atom. which is the second highest energy level? A. 1
B. 2
C. 3
D.4

it's c. elements are placed in rows based on how may valencies electrons have.

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"