Atoms Atomic Structure
What are the particles that make up all matter?
118 Known Atoms Each atom has a different number of protons 118 different kinds of atoms = 118 different elements on Earth
Basic Structure The center of the atom is called the nucleus The nucleus is surrounded by a an “electron cloud”
3 Subatomic Particles Three kinds of particles make up any atom Protons Neutrons Electrons These particles are called “subatomic particles” because they are smaller than an atom
In the Nucleus Protons are located in the nucleus and have a positive charge Neutrons are located in the nucleus and have no charge (they are neutral).
In the Electron Cloud Electrons are located in the space surrounding the nucleus called an electron cloud. Electrons have a negative charge
Size and Mass Protons are much bigger than electrons Protons and neutrons are about the same size
Comparing Subatomic Particles