basic chemistry all living things are made from chemical compounds

BASIC CHEMISTRYAll living things are made from chemical compounds

The small stuff

• Atom- is the basic unit of matter

Parts of an atom

• Even though atoms are small they contain– Protons(+)– Neutrons (no charge)– Electrons (-)

Elements

• Pure substances consisting of one type of atom.

The BIG 10 Elements

1. Potassium- K

2. Oxygen- O

3. Nitrogen- N

4. Gold- Au

5. Sodium- Na

6. Hydrogen- H

7. Carbon- C

8. Chlorine- Cl

9. Calcium- Ca

10. Iron- Fe

Chemical compounds

• Substance formed when two or more elements are chemically combined.– Examples:

• C6H12O6 - sugar

• H20 – water

• NaCl – table salt

Chemical Bonds

• Ionic- electrons are transferred

• Covalent – electrons are shared

• Van- der Waals- slight attraction between opposite charges– Ex: Geckos

Amazing Water

• Water is the most abundant compound on earth!

Hydrogen Bonds

• Enable water to attract other water molecules

Cohesion

• Water molecules seem to stick together– Why water beads– Why it hurts to do a belly flop

Adhesion

• Water is attracted to other molecules

– Water sticks to the side of a water bottle

Solutions

• Mixture – two or more elements that a physically combined.

Solutions

• Mixture in which the molecules are evenly distributed– Solute- what's dissolved– Solvent- what does the dissolving

• Water is the greatest solvent on EARTH!

Today’s Lab

• You will be working with your table mate. You will need:

–One of each of the cups from the back counter.

–Two pennies (get them from me)

–Lab sheet

Acids and Bases

PH scale

• Measurement system used to indicate the concentration of H+ ions in a solution.

Acid

• Contains higher concentration of H+ ions

• Has a ph value BELOW 7– Example- gastric acid (stomach acid)

Bases

• Contains OH- ions• Has a ph above 7

– Example : baking soda

Buffer

• Prevents sharp changes in PH

Human body

• The ph of human blood MUST be kept between 7.35 to 7.45 pH.

• Below or above this range means symptoms and disease. If blood pH moves to much below 6.8 or above 7.8, cells stop functioning and the patient dies.

Today's Lab

• Today you will be testing the ph of different liquids.

• Some are even items you drink on a daily basis!!!!