Stratospheric Ozone What is ozone? What does it do? What are its properties? How is it made? How is it destroyed? Why do Ozone Holes form primarily at the poles? Where is the ozone hole the largest? Many, many other questions ….

Ozone? … And if prehistoric Man merely got a sunburn, how is that we are going to destroy the ozone layer with our air conditioners and underarm deodorants and cause everybody to get cancer? Obviously were not … and we cant … and its a hoax. Evidence is mounting all the time that ozone depletion is, if occurring at all, is not doing so at an alarming rate.… Rush Limbaugh, See I told you so.

Basic Atomic Theory Atoms – Derived from greek word Atomos (indivisible). Simplest building blocks of matter All atoms of a same type are identical Atoms are not changed by chemical reactions Atoms cannot be created nor destroyed in chemical reactions (law of conservation of mass) Compounds form when elements combine

Relative size of a nucleus and an Atom

Atomic Structure (composition)

Protons and Elements The number of protons in the nucleus defines the element type. All Atoms with the same number of protons are the same element.

Atomic structure continued Lets consider oxygen 8O8O 16

Molecular Models

Covalent Bonding

Systematic Drawing of Lewis Structures Lewis structures show bonding and placement of electrons in molecules. 1. Sum Valence electrons for all atoms in the molecule 2. Draw the skeleton structure showing which atoms are bonded to each other. (Atom written first – generally center) 3. Complete the octet of all atoms surrounding the central atom 4. Place any left over electrons on the central atom 5. If the central atom has less than 8 electrons, complete the octet of the central atom by sharing additional pairs of electrons with the outer atoms.