Atoms Build Our World Look around you Take a deep breath Listen closely Everything you see smell hear taste and touch is matter Matter makes up the universe from the tiniest speck of dust to the largest stars in space Naming the Atom A man named Democritus in Ancient Greece named the atom A means not and tomos means cut in Greek Atoms are the smallest things that cannot be cut or destroyed 4
All matter is made up of atoms Atoms function like tiny building blocks They are so small you cannot see them with just your eyes It would take fi ve million of the smallest atoms to cover the tip of a needle Atoms fi t together like Legos to create larger pieces of matter Even Legos are made of atoms But atoms are not shaped like rectangles They actually look like tiny solar systems 5
Instead of a sun atoms have a nucleus in the middle The nucleus contains neutrons and protons two types of particles Particles are the tiniest pieces of matter we can count Particles called electrons rotate rapidly around the nucleus just as planets revolve around the sun Nucleus Protons Electrons Neutrons 6
There are 118 different kinds of atoms Each kind is called an element The number of protons in the nucleus determines which element an atom is The smallest element hydrogen has only one proton Another element helium has two protons Oxygen has eight protons Helium Seeing Atoms Scientists use a special microscope called an electron microscope to see atoms They use beams of electrons instead of beams of light 7
