BIO-1120: Chapter 3

  1. Polar Covalent Bonds
    a covalent bond between atoms that differ in electronegativity; the shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive
  2. Polar Molecule
    a molecule (such as water) with an uneven distribution of charges in different regions of the molecule
  3. Surface Tension
    a measure of how difficult it is to stretch or break the surface of a liquid; water has a high surface tension because of hydrogen bonding of surface molecules
  4. Kinetic Energy
    the energy associated with the relative motion of objects; moving matter can perform work by imparting motion to other matter
  5. Thermal Energy
    kinetic energy due to the random motion of atoms and molecules; energy in its most random form
  6. Temperature
    a measure in degrees of the average kinetic energy (thermal energy) of the atoms and molecules in a body of water
  7. Heat
    the thermal energy in transfer from one body of matter to another
  8. Calorie (cal)
    the amount of heat energy required to raise the temperature of  1 g of water by 1 degree Celsius; also the amount of heat energy that 1 g of water releases when it cools by 1 degree Celsius; the Calorie (with a capital C), usually used to indicate the energy content of food, is a kilocalorie
  9. Kilocalorie (kcal)
    a thousand calories; the amount of heat energy required to raise the temperature of 1 kg of water by 1 degree Celsius
  10. Specific Heat
    the amount of heat that must be absorbed or lost for 1 g of a substance to change its temperature by 1 degree Celsius
  11. Heat of Vaporization
    the quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state
  12. Evaporative Cooling
    the process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest kinetic energy changing from the liquid to the gaseous state
  13. Solution
    a liquid that is homogeneous mixture of two or more substances
  14. Solvent
    the dissolving agent of a solution; water is the most versatile solvent known
  15. Solute
    a substance that is dissolved in a solution
  16. Aqueous Solution
    a solution in which water is the solvent
  17. Hydration Shell
    the sphere of water molecules around a dissolved ion
  18. Hydrophilic
    having an affinity for water
  19. Molecular Mass
    the sum of the masses of all the atoms in a molecule; sometimes called molecular weight
  20. Mole (mol)
    the number of grams of a substance that equals its molecular or atomic mass in daltons; a mole contains Avogadro's number of molecules or atoms in question
  21. Molarity
    a common measure of solute concentration, referring to the umber of moles of solute per liter of solution
  22. Hydrogen Ion
    a single proton with a charge of 1+; the dissociation of water molecule (H2O) leads tot the generation of a hydroxide ion (OH-) and a hydrogen ion (H+); in water, H+ is not found alone but associates with a water molecule to form a hydronium ion
  23. Hydroxide Ion
    a water molecule that has lost a proton; OH-
  24. Hydronium Ion
    a water molecule that has an extra proton bound to it; H3O+, commonly represent as H
  25. Acid
    a substance that increases the hydrogen ion concentration of a solution
  26. Base
    a substance that reduces the hydrogen ion concentration of a solution
  27. pH
    a measure of hydrogen ion concentration equal to -log [H+] and ranging in value from 0 to 14
  28. Buffer
    a solution that contains a weak acid and its corresponding base; a buffer minimizes changes in pH when acids or bases are added to the solution
  29. Ocean Acidification
    decreasing pH of ocean waters due to absorption of excess atmospheric CO2 from the burning of fossil fuels
Card Set
BIO-1120: Chapter 3