Vocabulary  Write the terms and definitions for each vocabulary word from sections 2-1, 2-2 and 2-3. Keep these pages in your vocabulary divider.  Extra credit if you use this format (1/2 pt. for each term)

Chapter 2 The Chemistry of Life 2-1: THE NATURE OF MATTER

Atoms  KeyC#1: What three subatomic particles make up atoms?  The subatomic particles that make up atoms are protons, neutrons and electrons.  Atom: basic unit of matter  Protons: (+) charge  Neutrons: no charge (neutral)  Electrons: (-) charge  How small is an atom??  how-small-is-an-atom how-small-is-an-atom  Sketch figure 2-1 in your lecture notes.

Elements and Isotopes  What are elements?  Let’s look at the periodic table of elements. (Appendix G)  KeyC#2: How are all the isotopes of an element similar?  Because they have the same number of electrons, all isotopes of an element have the same chemical properties.  Facts to know about elements:  Atomic number = # of protons  Atomic mass = sum of protons & neutrons  Isotopes differ in the number of neutrons  Some isotopes are radioactive  Let’s practice with some of the elements…

Chemical Compounds  What is a chemical compound?  What are some examples of chemical compounds?  Physical and chemical properties of a compound are usually very different from those of the elements from which it is formed. (i.e. Na & Cl)

Chemical Bonds  What holds atoms together?  What is the key player in these bonds?  KeyC#3: What are the two main types of chemical bonds?  Ionic and covalent bonds  Ionic bonds: transfer of electrons  Covalent bonds: sharing of electrons  Let’s look at figures 2-3 & 2-4  What are molecules?  What does sharing electrons mean?  Electrons will travel in both orbits  2 electrons = single bond  4 electrons = double bond  Van der Waals forces: oppositely charged regions of molecules attract each other (intermolecular attraction)

Chapter 2 The Chemistry of Life 2-2 PROPERTIES OF WATER

The Water Molecule  How is water neutral?  KeyC#1: Why are water molecules polar?  Uneven distribution of electrons between the hydrogen and oxygen atoms.  Oxygen (-)  Hydrogen (+)  Let’s draw!  Why are polar molecules attracted to each other?  What is the difference between COHESION and ADHESION?  What are some examples of each?  makes-water-behave-strangely- christina-kleinberg#watch makes-water-behave-strangely- christina-kleinberg#watch

Solutions and Suspensions  What is a mixture? Give me some examples of mixtures.  Physically mixed, but not chemically combined  Solution: solutes evenly distributed throughout the solvent (i.e. salt water)  Solute is diluted  Solvent is the disSOLVEr  Suspensions: materials that do not dissolve but are suspended (i.e. blood)

Acids, Bases, and pH  What is the range of the pH scale?  What is an acid?  Substance with more H+ ions than pure water. pH < 7  What is a base?  Substance with lower concentrations of H+ than pure water. pH > 7  What do buffers do?