1. Chemistry Review Guide

2. ATOMS Basic unit of matter Construct: H atom C atom O atom

3. Chemical Reactions What is a chemical reaction? Reaction which results in a new substance with different physical & chemical properties Reaction which results in a new substance with different physical & chemical properties

4. Chemical Reactions What are reactants? Its what you start with in a rxn Its what you start with in a rxn What are products? Its what you end up with in a rxn Its what you end up with in a rxn C 6 H 12 O 6 + 6O 2  CO 2 + H 2 O66

5. Chemical Reactions What is an exergonic reaction? Heat is released (feels hot) Heat is released (feels hot) What is an endergonic reaction? Heat is absorbed (feels cold) Heat is absorbed (feels cold)

6. pH, Acids, Bases, Neutralization What is the pH scale? Scale that relates H + ions in solution What is an acid? Forms H + ions (0 to 6.9) Ex. HCl

7. pH, Acids, Bases, Neutralization What is a base? Forms OH - ions (7.1 to 14) Ex. NaOH What is neutralization? pH 7

8. Bonding What is an IONIC bond? Transfer of electrons

9. Bonding What is an ION? Charged particle – has lost or gained electrons What is a COVALENT bond? Share electronsoccurs in living organisms; is very strong!

10. Bonding Construct 1 Li and F atoms Illustrate ionic bonds using Li and F atoms Construct 1 C and 4 H atoms Illustrate covalent bonds using 1 C and 4 H atoms

11. Bonding What is a hydrogen bond? Weak bond – attraction between + and – What is a polar molecule? “poles” – unequally charged areas (+, -)

12. Bonding Why is water a polar molecule? Slight negative charge from the oxygen; slight positive charge from the 2 hydrogens Mickey Mouse!

13. Why do molecules of water form hydrogen bonds? Because water is polar, therefore it forms a polar molecule: there is an attraction between the positive and negative ends of the water molecules Bonding

15. Bonding Construct 4 water molecules Use “+” and “-” signs to show polarity of parts of the water molecules Draw in the hydrogen bonds between the molecules using a dashed line

16. Properties of Water What is cohesion? Water is attracted to other water molecules What is adhesion? Water is attracted to other substances (ex. Glass)

17. Properties of Water What is surface tension? Barrier that is produced from cohesion of water molecules Ex. Water strider walking on water Ex. Water strider walking on water

18. Properties of Water What is the evaporative cooling property of water? Water removes heat from the environment (ex. Sweating)

19. Properties of Water Why does ice float and why is it important in biology? Ice is less dense than water: all life on Earth would be killed if it sank!!

20. Properties of Water Place a capillary tube in colored water. Put a drop of water on a slide. Put another slide on top. Let go of the bottom slide. Try to float paper clips on water. Drop water on penny. See how many drops you can get.