Chemistry

• Electron (-)

  > subatomic particle with a negative electric charge

  > # of electrons = #of protons

  Then it makes them neutral
• Proton (+)

  > subatomic particle with a positive electric charge

  > number of proton in an atom determines the atomic number and each element has a unique number of protons
• Neutron 

  > subatomic particle with no electric charge meaning it is electrically neutral 

  > number of neutrons, together with the number of proton determines the atomic mass of an atom
• Kinetic Molecular Theory of Matter

  > concept that basically states that matter is composed of a very large number of very tiny particles, molecules or ions.
•  Liquids - have slower molecules which roll over each other
• Liquids have fixed volume but take the shape of container and gravity pulls them down to the bottom
• Solids - have slow moving molecules which vibrate around their position
• 1. Solids have fixed volume and shape and gravity pulls them down to the bottom of the container
• • Polarity of a molecule is a measure of the distribution of electric charge within the molecule
• Dipole moment

  > consequence of the unequal sharing of electrons in a covalent bond. If one atom in a bond is more electronegative than the other, it attracts the shared electrons more strongly, creating a dipole.
• Linear Molecules

  • Nonpolar if the ends are the same
  • Polar if the ends are different
• Tetrahedral

  • Nonpolar if all 4 corners are the same
  • Polar if even 1 corner is different
• Trigonal Pyramids

  • Always polar
• Bent Molecules

  • Always Polar
• Inter

  • Means between or among
  • Often used to indicate interaction or connection between 2 or more things
• Molecule - two or more atoms connected by chemical bonds
• Forces

  • a force is a push or pull that can cause an object with mass to change its velocity, which includes starting or stopping the object’s motion or changing its direction
•  Intermolecular Forces  are attractive or repulsive forces that exist between molecules, influencing their physical and chemical properties.
• Intermolecular Forces / Van Der Waals forces  named after the physicist Johannes Van Der Waals
• 1. Dipole-Dipole Interaction

  > forces occur when the partially positive charged part of a molecule interacts with a partially negatively charged of the neighboring molecule
• Dipole-Induced Dipole Interaction

  >  a weak attraction that results when a polar molecule induces a dipole in an atom or in a non polar molecule by disturbing the arrangement of electors in the non polar species

  > Polar-non polar interaction
• Dispersion Forces

  > can be called london dispersion forces

  > arise from temporary variations in electron density in atoms and molecules

  > non polar non polar
• Ion-Dipole attraction

  > occurs between ion and partial charges of polar molecules

  > force is significant in solutions where ionic compounds are dissolved in polar solvents

  > attraction btween charged ion and partial charges on polar molecules 
• Ion induced dipole attraction

  > weak attraction that results when the approach of an ion induces a dipole in an atom or in  a nonpolar molecule by disturbing the arramgeent
• 1. Hydrogen Bonding

  > special type of dipole-dipole attraction

  > occurs when HYDROGEN is DIRECTLY bonded to a highly electronegative atom such as (N,O, or F) hydrogen carries a partial positive charge and the electronegative atom carries a partial negative charge resulting in a strong dipole-dipole interaction