1. atom
    consists of a nucleus positively charged protons and neutrally charged neutrons. negatively charged electrons are arranged outside of the nucleus
  2. molecules
    groups of two or more atoms held together by chemical bonds
  3. electronegativity
    • ability of an atom to attract electrons
    • 3 kinds of bonds: ionic, covalent, hydrogen
  4. ionic bond
    • bonds formed between two atoms when one or more electrons are transferred from one atom to the other. occur when electronegativity is very different and one atom has a much stronger pull.
    • atom that gains electrons has a negative charge
    • atom that loses electrons has a positive charge
    • ex. Na+ Cl- = NaCl
  5. Covalent
    • form when electrons between atoms are shared. occurs when electronegativities are similar.
    • -nonpolar covalent bond
    • -polar covalent bond
  6. nonpolar covalent bons
    • bonds form when electrons are share equally. when the 2 atoms sharing electrons are identical
    • ex. O2
  7. polar covalent
    bonds are formed when electrons are shared unequally. different electronegativities and an unequal distribution of the electrons results
  8. hydrogen bond
    weak bonds between molecules. form when a positively charged hydrogen atom in one covalently bonded molecule is attracted to a negatively charged area of another covalent bond
Card Set
AP bio