November 17, 2017 Journal: What special property of water causes it to stick together and form a ball when placed on wax paper?

Chemical Reactions

Physical Change A change in size, shape, or state of matter that does not result in a new substance being formed

Chemical Change A change in the physical and chemical properties of a substance so after the reaction takes place a new substance is formed

Chemical Reaction The process of rearranging the bonds within two or more substances in order to form at least one new substance

6CO2 +6H20  C6H12O6 + 6O2 The number before the compound tells you how many there are of each compound Atomic symbols tell what elements are in the compound Subscripts tell how many of each element are in the compound ***Must have an equal number of each element on both sides of the reaction

Reactants A substance that is present at the beginning of a chemical reaction

Products A substance that is formed during a chemical reaction

Conservation of Mass Matter cannot be created or destroyed, only rearranged

Acids and Bases

pH H2O will sometimes split to form H+ and OH- In pure water, H+ = OH- , so water is neutral pH scale is based on the number of H+ and OH- in solution

Acids and Bases An acid has more H+ while a base has more OH-

pH scale Ranges from 0 - 14 7 is neutral (water) pH < 7 = acid pH > 7 = base Based on a factor of 10

Acids Highly corrosive Burning Sour taste Ex. HCl, acetic acid, citric acid

Bases Feel slippery Bitter taste Very few foods, some medicine Ex. Oven cleaner, bleach

pH in an organism Most cells work best around pH 7 Too high or too low pH cause enzymes in the body to stop working To prevent large pH swings, organisms use buffers