2. Scrie formulele structurale pentru izoalcanii: 3-etil-2,2 dimetilpentan 5-etil-2-metilheptan 2,2,3,3-tetrametilbutan 3,3-dimetiloctan 2,2,4-trimetilpentan CH3 | CH3 – C – CH – CH2 – CH3 | | CH3 CH2 – CH3

whats the meaning of /

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.

the answer is na (sodium)