Notes
Review
- The identity of an element is determined by the number of protons
- Number of protons = Atomic number
- Number of protons = Number of Electrons in an atom
- Number of Protons does not equal the Number of electrons in an ion
- An atom becomes an ion when it gains (-) or loses (+) electrons
- Electrons are gained or lost from the outer shell (Valence shell)
- Atoms gain/lose electrons to become ions so they can form bonds with other atoms
- Mass-Protons = Neutrons
- Number of neutrons changes in an isotope
- Number of electrons changes in an Ion
- The mass of an element is actually an average of all the isotopes that exist
- Average atomic mass = Mass of an isotope X% abundance (all added together)
- Alkali Metals have a +1 charge because they lose one outer shell valence electrons
- Alkali Earth Metals have a +2 Charge because they lose 2
- Halogens have a -1 charge because they gain 1 electron
- Noble gasses have 8 outer shell electrons so they don’t gain or lose electrons (no bonding)
- Eight is great but two will do