chapter 2 : chemistry

Chapter 2 : Chemistry

Biology

Intro

• Democritus believed “that all things were made up of the same “pure essential substances”

• Greek word “atomos” means to cut

EVERYTHING is made of atoms

• Cells, paper, rocks, squirrel, cheese, hair, chair ….

• How many kinds of atoms? Well there is a limited amount… we organize them on the Periodic Table • There are 92 that occur naturally • …and 117 as of 10/2006

Periodic Table What page in your book ?

Back to atoms…

• How small are they?• How can we see them?• What are they made of …

-100 million side by side would only be 1cm

-Scanning tunneling microscopy

- Protons neutrons electrons

Atoms

• Resemble a solar system…. Some people say…• Nucleus- center…… Electron Cloud- space

outside

• Inside: Protons, and Neutrons• Outside: Electrons – constantly moving in orbits

• Sizes: P are much bigger than E• Where is most of the mass? Inside/outside?

3 particles review

Negative Charge -

outsideElectrons

Neutral: No charge

InsideNeutrons

Positive charge

+

InsideProtons

Charges

• ++, _________ -- _________ +- _______

• Magnets• “Opposites Attract’ • David Blaine and levitation• http://www.metacafe.com/watch/1

340/david_blaine_levitate/

Other famous people…• Russell Simmons: Vegas• Joey Fatone : N Sync- NYC• Trevor: Blink 182- Vegas• Billy Dee Williams: Hoboken• Sean Puffy Combs- NYC• Tony Soprano - Belleville filming • Sopranos - Nutley Queen Margarita• Ricki Lake – NYC• Gerard Way- My chemical romance

Atom/element/compound

• Atom: • Element: only 1 kind of atom… “pure”• Compound: red is O, and H is orange

• Made up of more than 1 kind of atom in definite proportions…

Gold: Au Pt: ?• Is your jewelry pure gold?

• Why are platinum rings better than gold?

No. Its an “alloy”

Gold by itself is actually too soft to wear as jewelry..

Which of these has the most amount of gold 10k, 14k, 24k ?

When you scratch gold, its so soft, you are actually leaving it behind. Platinum is a harder metal and more rare, no scratches.

Why are certain things of the periodic table so valuable?

• Elements: can’t make it …. (maybe a well trained scientist)

• Found in nature- “low supply”• FYI….Black gold- “oil”- low supply

(not an element)• Weather Channel- the elements…

• According to the Empedocles, a Greek philosopher, scientist and healer who lived in Sicily in the fifth century B.C., all matter is comprised of four  "roots" or elements of earth, air, fire and water.  

• He associated these elements with four Greek gods and goddesses - air with Zeus, earth with Hera, fire with Hades, and water with Nestis (believed to be Persephone):