Atomic Structure

• All atoms have a nucleus containing protons and neutrons.
• Electrons surround the nucleus in orbits/energy levels.
• Almost all of the mass is in the nucleus of an atom.
• Protons have a relative charge of +1.
• Neutrons have a relative charge of 0.
• Electrons have a relative charge of -1.
• Protons have a relative mass of 1.
• Neutrons have a relative mass of 1.
• Electrons have a relative mass of 1/1840.