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)

© 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 –Low concentration of hydrogen ions (H+) 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– Before reaction Products– After reaction Catalyst– Helps energize reaction Metabolism– Maintain life 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 Ex: Cellular Respiration & Photosynthesis