How things blow up!! Not really… Bonds Compound Reactions

Bond an attachment among atoms Compound - a group of atoms with an exact number and type of atoms in it arranged in a specific way Mixture - any combination or blend of different elements

ionic bond An attraction between ions of opposite charge. Ionic bond formation involves transfer of electrons Examples - salt, baking soda and lithium chloride http://www.atech.org/faculty/dunne/chembond/page8.htm

covalent bond A covalent bond is a very strong attraction between two or more atoms that are sharing their electrons. Examples - water,methane,carbon dioxide, and ammonia http://www.wikipedia.org/wiki/Covalent_bond

Chemical reactions highlight patterns in chemical behavior Combination reactions Decomposition reactions Rearrangement reactions Displacement reactions

Combination reactions - build a compound from simpler compounds or elements A + B C 4 H2 + 4 Cl2 8 HCl Decomposition reactions - break a compound into simpler fragments C A + B 4 H2O2 4 H2O + 2 O2 Rearrangement reactions - making and breaking bonds within a compound. A B HOONO HNO3

Displacement reactions involve replacement or swapping of parts of a compound. A + BC AB + C AB + CD AD + BC NaOH + HCl H2O + NaCl

ENERGY OF CHEMICAL REACTIONS Energy is absorbed or released in chemical reactions Endothermic Reactions energy is absorbed product feels cold Exothermic Reactions energy is released product feels HOT

Law of Conservation of Mass In a chemical reaction, matter is neither created nor destroyed Balancing chemical equations Same number of elements on both sides of the equation H2 + O2  H2O Step 1. List the elements in the equation H O Step 2. Determine the number of element on each side H 2 2 O 2 1 Step 3. Balance away…. 2 H2 + O2  2 H2O