Answer:
5) A chemical that cannot be broken down or separated into other chemicals
Step-by-step 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.