basic chemistry all living things are made from chemical compounds
TRANSCRIPT
BASIC CHEMISTRYAll living things are made from chemical compounds
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
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!!!!