What is the basic form of matter which cannot be broken down any further?

The smallest form of matter that cannot be broken down any further is an atom.

Atoms or molecules

Examples: Gold, Oxygen, Carbon

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.

im pretty sure its b