Which statement describes the electron sea model for metallic bonding?

-this model involves electrons held tightly between atoms.
-this model explains all properties of metals.
-this model involves electrons moving among bands of orbitals.
-this model is the simplest model.

This model is the simplest model.

(This is the answer just took the test)

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.