Atoms, Ions, Molecules
Atom● The basic unit of matter● Structure:
○ protons- have a + charge○ neutrons- have no charge
■ protons and neutrons form the nucleus○ electrons- have a - charge
■ move around the nucleus in energy levels
Element● Atoms with the same characteristics● Have the same # of protons
○ protons give atoms their identity○ changing # of electrons = ion○ changing # of neutrons = isotope
● Carbon, oxygen, nitrogen, and hydrogen make up 96% of your body
Element
Isotope
Electrons● The cause of all chemical
reactions and bonds.● Octet rule: Atoms want 8
electrons in their outer energy level○ the first energy level only
wants 2
Electrons● Atoms gain or lose electrons to fulfill the
octet rule● Molecule- Two or more atoms bonded
together● Compound- Two or more elements bonded
together
Ionic Bonds● A bond between ions● Ion- an atom that gained or lost an electron● Cation- atom that loses an electron, has a +
charge● Anion- atom that gains an electron, has a -
charge
Ionic Bonds
Ionic Bonds
Ionic Bonds● The cation and anion are attracted to each
other and bond.
Covalent Bonds● Atoms bond by sharing electrons● Shared electrons fill the outer energy levels