Electrons

• Electrons are one of the smallest parts of the atom. They carry a negative electric charge, and circle the atom in a shell. Electrons covalently bond with other atoms.
  
  

Protons

• Protons are much larger than electrons. Protons carry a positive charge. These elements of the atom are included within the nucleus. They are not included in bonding, but they are a part of the atomic number of an atom.
  
  

Neutrons

• Neutrons hold no charge, and they are found in the nucleus of the atom. These particles are slightly heavier than the proton. Neutrons are a part of an atom's isotope.
  
  

Isotopes

• Isotopes are atoms that are the same element, but they have a different number of neutrons. For instance, carbon 14 is an isotope with more neutrons.
  
  

Bonds

• Two types of bonds can happen between atoms. An ionic bond is one in which two opposite charges combine. For instance, sodium and chlorine combine in an ionic bond to form salt. Covalent bonds are two atoms that share electrons. An example is carbon and oxygen.