1. Chapter 2: Chemistry Matter: Anything that has mass and volume
Mass – amount of matter
Volume – how much space it occupies
Weight?  pull of gravity
Characteristics:
Physical Properties – mass, volume, color, odor, shape, texture, taste, hardness, melting point, boiling point, phase (solid, liquid, gas)
Chemical Properties – describe a substances ability to change into a new substance as a result of a chemical change

3. Chemical Changes

4. Physical Reaction / Chemical Reaction?
Chapter 2: Chemistry
Physical Reaction / Chemical Reaction?

5. Physical vs. Chemical Changes
Aluminum foil is cut in half
Milk goes sour
Gasoline is ignited
Clay is molded into a new shape
Butter melts on warm toast
You take an antacid to settle your stomach
Water evaporates from the surface of the ocean
Rust forms on a nail left outside
A juice box in the freezer freezes
Rubbing alcohol evaporates on your hand
Physical
Chemical
Chemical
Physical
Physical
Chemical
Physical
Chemical
Physical
Physical

6. Chapter 2: Chemistry Atoms – smallest unit of matter
Protons – positively charged particles
Neutrons – no charge
Electrons – negatively charged particles
Atomic number - # of protons
Atomic mass - # of protons + neutrons

7. Chapter 2: Chemistry Chemical Elements: Isotopes Radioactive Isotopes
Made up of 1 type of atom
Isotopes
Have same #’s of protons and electrons, but differ in # of neutrons
Radioactive Isotopes
Can be good or bad
Age of fossils – C14
Medically – diagnose & treat
Radiation given off can damage molecules/DNA

8. Chapter 2: Chemistry Compounds and molecules:
Made up of 2 or more elements
Ionic and covalent bonding
Ionic - Give and take of electrons ( Na Cl )
Covalent – Sharing of electrons

9. Chapter 2: Chemistry Chemical Reactions Structural Formulas
Anytime a chemical bond is formed or broken a reaction occurs:
Reactant + Reactant = Product
Na Cl = NaCl
Structural Formulas
Shows arrangement of elements in a compound

10. C H O N Chapter 2: Chemistry 6 12 1 8 16 7 14
Elements that make up the human body C 6 12 H 1 O 8 16 N 7 14
Protons
(P + N) 6P 6N 8P 8N 7P 7N 1P 0N

11. Chapter 2: Chemistry
Colored Pencils: Color elements at top of page, then color amount of that element found in a shrub and a rabbit
Hydrogen: White
Oxygen: Blue
*Carbon: Black
Nitrogen: Red
Phosphorus: Green
Calcium: Purple

12. Isotope – different # of P & N Ion – a charged particle P ≠ E
Same!
Element
Atomic Number
(# of P)
Mass Number
(P+N)
Number of Protons
(+)
Number of Neutrons
(mass # - protons)
Number of Electrons
(-)
Ion, or Neutral Atom
Aluminum
(Al) 13 27
Neutral atom
Bromine
(Br) 35 45 36
Carbon
(C) 6 14 13 14 35 80
Ion (-) 12 6
Neutral atom
Isotope – different # of P & N
Ion – a charged particle P ≠ E
Neutral Atom – P = E

13. Isotopes, Ion, or Neutral Atom
Same!
Element
Atomic Number
(# of P)
Mass Number
(P+N)
Number of Protons
(+)
Number of Neutrons
(mass # - protons)
Number of Electrons
(-)
Isotopes, Ion, or Neutral Atom
Helium
(He) 2 4
Neutral atom
Hydrogen
(H) 1
Lithium
(Li) 3 7
Isotope – different # of P & N
Ion – a charged particle P ≠ E
Neutral Atom – P = E

14. Isotopes, Ion, or Neutral Atom
Same!
Element
Atomic Number
(# of P)
Mass Number
(P+N)
Number of Protons
(+)
Number of Neutrons
(mass # - protons)
Number of Electrons
(-)
Isotopes, Ion, or Neutral Atom
Nitrogen
(N) 14
Neutral Atom
Oxygen
(O) 18 8 16 6
Potassium
(K) 39 19
Isotope – different # of P & N
Ion – a charged particle P ≠ E
Neutral Atom – P = E

15. Chapter 2: Chemistry - Water  H2O Polarity +
The oxygen side of the molecule is negative and the Hydrogen side is positive
With 8 Protons in its nucleus, an oxygen atom has a much stronger attraction for electrons than does the hydrogen atom with a single proton in its nucleus. H O + -

16. Chapter 2: Chemistry
A water molecule is polar because there is an uneven distribution of electrons between the oxygen and hydrogen atoms.
Because of their partial positive and negative charges, polar molecules such as water can attract each other

17. Strong attraction between water molecules produces surface tension
Chapter 2: Chemistry
Cohesion – an attraction between molecules of the same substance.
Strong attraction between water molecules produces surface tension

18. Chapter 2: Chemistry
Cohesion at work!

19. Chapter 2: Chemistry
Adhesion – an attraction between molecules of different substances.

21. Chapter 2: Chemistry Water is often found as a mixture
Mixture – material composed of two or more elements or compounds that are physically mixed together, but not chemically combined.
Two types of mixtures that can be made with water:
Solutions
Suspensions

22. Chapter 2: Chemistry Solution:
Mixture of two or more substances in which the molecules of the substances are evenly distributed.
Solute – Dissolved matter in a solution
(thing being dissolved)
Solvent – does the dissolving
***Water is the universal solvent

23. Chapter 2: Chemistry Suspensions
A mixture of water and non-dissolved materials

24. Chapter 2: Chemistry + H+ H2O + OH- Acids, Bases and pH water
Hydrogen ion
Hydroxide ion
water +

25. Chapter 2: Chemistry Acids Any compound that forms H+ ions in solution
Higher concentrations of H+ ions than water
Have pH values below 7
Bases
Any compound that forms OH- ions in solution
Lower concentrations of H+ ions than water
Have pH values above 7

26. Chapter 2: Chemistry
pH Scale:

27. Chapter 2: Chemistry Buffers:
Chemical substances made by the body to regulate pH