Chemistry Review Unit 3, Lesson 1

© 2007, CSCOPE Elements 90 occur naturally 25 essential to living organisms C,H,O,N make up 96% of a human body C HOPKINS CaFe Mighty Salt (Mg NaCl)

© 2007, CSCOPE Periodic Table Atomic Number (number of protons) Atomic Mass (total of protons and neutrons) Isotopes – different number of neutrons

© 2007, CSCOPE Atoms Nucleus –Protons (positive charge) –Neutrons (no charge) Energy levels –Electrons (negative charge) –1st level up to two electrons –2nd level up to eight electrons –3rd level up eighteen electrons (needs 8 to be stable)

© 2007, CSCOPE Atoms continued –Number of proton and electrons are equal –Atoms have no electrical charge

© 2007, CSCOPE Compounds Molecule –covalent bond –bond is strong Ionic Compound –ionic bond –bond is weak

© 2007, CSCOPE Solutions and Suspensions Mixture - Individual substances retain own properties Suspension – mixture in which materials do not dissolve Solution - substances evenly distributed –Solute (substance dissolved) –Solvent (substance in which solute is dissolved)

© 2007, CSCOPE Acids and Bases pH 0-14 Acids –less than 7 pH –High concentration of hydrogen ions (H+) Bases –greater than 7 pH –High concentration of hydroxide ions (OH-) pH of 7 is neutral (water)

© 2007, CSCOPE Water Polar compound Hydrogen bonding Cohesion Adhesion Capillary action Universal solvent –carries nutrients –removes wastes Most abundant substance in body Needed for digestion Regulates temperature

© 2007, CSCOPE Chemical Reactions Reactants Products Catalyst Metabolism C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + energy 6CO 2 + 6H 2 O + energy C 6 H 12 O 6 + 6O 2