The Chemistry of Life Unit 1 Chapter 2 Part 1

A. Basic Chemistry Chemistry – central science Matter Anything with mass and takes up space 4 states of matter – depend on amount of thermal energy Solid Liquid Gas Plasma

c. Elements and atoms 1) Element – pure substance that can’t be broken down farther by ordinary chemical reactions 2) Atom – smallest unit of an element that has the same characteristics as that element

a) Nucleus i. Center of atom ii a) Nucleus i. Center of atom ii. Made of neutrons and protons b) Neutrons – no charge c) Protons i. Positive charge ii. Tell what element you have

d) Electrons i. Negative charge ii d) Electrons i. Negative charge ii. Orbit the nucleus in set energy level iii. Determines properties e) Mostly open space - If nucleus is the size of a tennis ball at 50 yrd line the electrons are pinheads by goal posts

f) Held together by opposite forces g) Proton – electron relationship i. Protons = electrons in a neutral atom ii. Stars and nuclear reaction changes number of protons iii. Possible to lose or gain electrons

3) Periodic table a) Lists the elements b) Organized by atomic number 4) Elements in living things (98%) a) Oxygen b) Carbon c) Hydrogen d) Nitrogen e) Calcium

d. Chemical bonding: Ionic 1) Atoms bond for stability 2) 8 electrons in outer shell gives stability (H only 2) 3) Ions – gain/lose electrons 4) Ionic bonding – bonding of ions 5) Weaker bonds 6) Salt

e. Chemical Bonding: Covalent 1) Sharing electrons 2) Very strong bonds 3) Single, double, triple bonds 4) Water, sugar, methane

f. Compounds 1) Made of 2 or more elements 2) Molecule – smallest unit of a compound 3) Properties are different than individual elements 4) Water and sugar 5) Molecular formulas a) H2O b) C6H12O6 c) (SO4)3 d) 7CO2

g. Chemical and Physical Changes 1) Chemical a) Atoms change - electrons b) Compound’s characteristics differ from its element’s – NaCl c) Bubbles, gives of light/heat, change in color, forms a precipitate

2) Physical Change a) Change of state b) Mixtures c) Can be separated

B. Energy 1. Ability to do work or cause a change 2. 2 kinds a. Kinetic energy (KE) – motion b. Potential energy (PE) – stored 3. Can be converted to the other

4. Thermodynamics a. Laws 1) Energy is can’t be created or destroyed 2) When energy is used some is lost b. When energy is used it increases entropy – burning a log

5. Kinetic molecular energy a. All atoms are moving b 5. Kinetic molecular energy a. All atoms are moving b. More heat = more energy = more moving c. Movement determines what state it will be in d. Absolute zero – no movement

6. Potential energy of molecules a. Stored in the bonds b 6. Potential energy of molecules a. Stored in the bonds b. Exothermic – gives off heat c. Endothermic – absorbs heat 7. Catalyst a. Effects rate of reaction but isn’t used b. Heat

C. Solutions Homogeneous mixture (blood) Solute – thing being dissolved Solvent – thing doing the dissolving Concentration – ratio of solute in the solvent Dilute

6. Diffusion a. Movement of molecules from high concentration to low concentration b. Stops once equilibrium is reached c. Concentration gradient – difference b/w the two areas d. Permeable – allows things to pass through

7. Osmosis a. Semipermeable b. Diffusion of water molecules c 7. Osmosis a. Semipermeable b. Diffusion of water molecules c. High to low concentration of water

Isotonic, Hypertonic, Hypotonic https://www.youtube.com/watch?v=QBAPBGa5SBA

D. Properties of Water Water is polar Molecule has a slight + and – side Oxygen pulls on electrons making it – and H + Creates H-bonds Weak bonds Form between + H atom and a slightly - atom O H _ +

3) Causes adhesion, cohesion, and high specific heat a) Adhesion b) Cohesion c) High specific heat i. Allows for homeostasis ii. Allows for temperature regulation 2. Polar and nonpolar substances don’t mix

E. Acids and Bases Acids Release H+ when dissolved H+ = proton Increase concentration of H+ 0 – 6.99 on pH scale more acidic stomach acid pH between 1 and 3

Decrease concentration of H+ 7.01 – 14 on pH scale 3. Neutral 2. Bases Decrease concentration of H+ 7.01 – 14 on pH scale 3. Neutral 7 on pH scale Pure water bile pH between 8 and 9 more basic

Virtual Lab Google “osmosis lab” Click on first link http://www.phschool.com/science/biology_place/labbench/lab1 /intro.html