What is an element? 1) a chemical that cannot be separated, but is limited in supply 2) a chemical that can be broken down or separated into other chemicals 3) one or more molecules held together by chemicals 4) two or more atoms held together by chemical bonds 5) a chemical that cannot be broken down or separated into other chemicals

5) A chemical that cannot be broken down or separated into other chemicals

Explanation:

Element:    

  When number of single type of atoms meet then they form element.Element is a pure substance.Element is the basic unit to form all other substances which exits in the world. These are the element which have same number of proton in the nucleus.Element can not be broken down or can not be separated in to other .

Ex: Oxygen(O) ,Hydrogen(H) ,Helium(He) ,Copper(Cu) ,gold(Au) ,Silver(Ag),Aluminium(Al) etc .

5) A chemical that cannot be broken down or separated into other chemicals.

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.