1. Chapter 2: Chemistry of Living Things

2. -Anything that has mass and takes up space
Matter
-Anything that has mass and takes up space

3. Atoms
Parts of an Atom
Nucleus
Electrons Shells
-Smallest particle of matter
-center of the atom
-Neutrons-neutral (0)
-Protons-positive (+)
-Electrons-negative (-)
-They move rapidly around the nucleus
-The further from the nucleus it is, the more energy it has

4. Ions
Charges
-Gain or loss of electrons
-(+) have fewer electrons
-(-)have extra electrons

5. Elements
Periodic Table
 You need to know
-a pure substance made of just one kind of atom
- Can predict the ability of atoms to react
 hydrogen
carbon
nitrogen
oxygen
sodium
potassium
sulfur
phosphorus
calcium

6. Isotopes
Radioisotopes
-atoms of the same element that differ in the number of neutrons they contain
-isotopes with unstable nuclei, their nuclei tend to release particles or radiant energy or both

7. Compounds
Example
-When two or more elements chemically combine to form a new substance
-If Na mixes with water it becomes explosive
-Cl is a poisonous green gas
-When you combine Na and Cl you end up with NaCl – table salt

8. Molecular Formula
Examples
-Shows the proportions of each kind of atom in a compound
-It is the proportion of atoms that give compounds their chemical personality
H2O (water) = 2 Hydrogen and 1 Oxygen
H2O2= 2 Hydrogen and
2 Oxygen

9. Mixtures
Solution
Solvent
Solute
Example
-Molecules of different substances mingling without combining chemically
-particles of one substance disperse in another substance to make a uniform mixture
-a substance that dissolves
-Water is a universal solvent
-a substance that gets dissolved
Sugar dissolves in water

10.  Energy   
Exergonic (exothermic)
Endergonic(endothermic)
Activation Energy
 -All atoms and molecules in any substance are in constant motion
(heat is a form of energy)
-Energy is never destroyed or created it only changes form
-release of energy
Example
-burning of wood
-feels hot
-use of energy
-Cellular reactions
-feels cold (in non-living things)
-energy required to start a chemical reaction

11. Chemical reactions
Ionic Bond
Covalent Bond   
Example
-process of breaking existing chemical bonds and forming new bonds
-when an atom transfers an electron to another atom
-Covalent-occurs when 2 or more atoms share an electron
-Covalent bonds do not break easily
-water H2O, each hydrogen gets it’s electron part of the time and oxygen gets it the other part of the time
-Usually there will be a slightly negative end (where the electron spends most of its time) and a slightly positive end to a molecule

12. Equations
Reactants
Products
Arrow
Symbols
-describe what happens in a chemical reaction
-do the reacting
- are produced during reaction, on right side of the arrow
-points in the direction of the products (always)
-Subscript-fixed number that tells the number of atoms of an element in one molecule
-Coefficients-the correct proportion of substances in the reaction

13. Acids and Bases
Acids (acidity)
Bases (alkalinity)
pH scale
-pH range of 0-7
-stomach pH2, Vinegar pH3, Urine pH6
-Chemical opposite of an acid
-Bases – Ammonia pH12, -Milk of magnesia pH10.5
-pH range of 7-14
-Below 7 is an acid
-7 is neutral (water)
-Above 7 is a base