Pb + H3PO4 》H2 + Pb3(PO4)2 what type reaction

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.

increased stability in the completion of fluorine's outer shell.

its first and third is your answer i did the qustion the fourth isnt right

може ли да зареждате повече информация, моля