1. Name Date Period Chapter 2 Take notes here Summary – one summary at the end Questions “Cornell Style”

2. States of Matter Solid -- definite shape & volume (tightly packed) Liquid -- definite volume (not as tightly packed) Gas -- no definite shape or volume (very “loose”)

5. Write a Question now!

6. Element – atoms which all have the same number of protons. 1 type of atom

7. n Tom Lehrer’s Element Song http://www.privatehand.com/flash/eleme nts.html http://www.privatehand.com/flash/eleme nts.html

8. Metals – are on the left side Non-Metals – are on the right side

9. Atomic number (# of P) Chemical symbol Atomic mass (# P+N) The # of electrons = # of protons 10 Ne 20.18

10. Atom – Model of an atom energy levels nucleus [ protons (+) & neutrons ] electrons (-) The smallest part of an element that has the properties of that element. “unable to cut”

11. Write a Question now!

12. Compound or NOT ? Carbon (C) Compound or NOT Water (H 2 O) Compound or NOT Salt (NaCl) Compound or NOT Sodium (Na) Compound or NOT Compounds - two or more elements The kinds of atoms and the proportions of atoms are fixed.

13. Number of atoms in a compound. H2OH2O NaCl C 6 H 12 O 6 CH 4 NH 2 CH 2 COOH (NH 4 ) 2 SO 4 3 2 24 5 10 15

14. Write a Question now!

15. Write a 2 sentence summary of these notes.

16. Worksheet -- Element and Their symbols Worksheet -- Number of atoms in a formula

17. Ionic Bonds Formed by a metal and nonmetal. There is an attraction between opposite charges. Examples: Na + + Cl - NaCl K + + Br - KBr Ca 2+ + F - CaF 2 “Opposites attract.”

18. Covalent Bonds Formed by two nonmetals. share one or more pairs of electrons Examples: Cl - Cl 2 O = O O2O2

19. Chemical Reactions – change one set of chemicals into another. Atoms are rearranged--- they are not created or destroyed! Na + + Cl - NaCl (reactants)(products) 2H 2 + O 2 2H 2 O

20. Write a Question now!

21. Like all molecules, water is neutral. Polar - an uneven pattern of charge Water is a very good dissolving agent. H H O H2OH2O

22. Hydrogen Bonding water molecules are attracted to each other because of its polar nature cohesion = attraction between similar substances adhesion = attraction between different substances Capillary action = cohesion and adhesion working together

23. Temperature Moderation water must gain or lose a large amount of energy for its temperature to change. Examples: swimming pools lakes ponds ocean This helps animals to maintain a stable temperature (homeostasis) despite outside temperature.

24. Write a Question now!

25. pH scale measures the concentration of hydrogen ions & hydroxide ions (acid) (base) (acid) (neutral) (base) 0 7 14 I I I I I I I I I I I I I I I Buffers -- are a weak acid or base that prevents a sudden change in pH Stomach acid Vinegar Soap Bleach Urine

26. Write a Question now!