1. Chapter 2 Chemistry of Life
2.1 Composition of Matter
2.2 Energy
2.3 Water and Solutions

2. Composition of Matter
Chapter 2
Composition of Matter
Matter: Anything that occupies space and has mass.
Mass: Amount of matter an object has.
Elements: Made of atoms & can not be broken down into simpler substances.

3. 6 Most common elements in organic molecules
Carbon
Hydrogen
Nitrogen
Oxygen
Phosphorus
Sulfur

4. Building blocks of matter Made of subatomic particles
Atomic Structure
Atom
Building blocks of matter
Made of subatomic particles
Proton (p+)
Neutron (n°)
Electron (e-)

5. Atomic Structure Particle Charge Location Mass Proton (+) Nucleus
1 amu
Neutron
None
Electron
(-)
Orbitals
1/1837 amu

6. The number of protons determines an element
Comparing Atoms
The number of protons determines an element
Atomic number =
# of protons 47 Ag
107.87
Atomic Mass #
= # p + # n

7. Isotopes
Isotopes are atoms of the same element that have different numbers of neutrons.
These are all isotopes of hydrogen.

8. Neutron number changes = Isotope Electron number changes = Ion
Ions
Neutron number changes = Isotope
Electron number changes = Ion
Ion (charged atoms)
Compare the number of protons & electrons
Positive charge: More protons than electrons
Negative charge: More electrons than protons

9. Ionic Bonding Transfer of electrons Bond between metal an non-metal
Composition of Matter
Chapter 2
Ionic Bonding Transfer of electrons Bond between metal an non-metal

10. Covalent Bonds Electrons are shared
Composition of Matter
Chapter 2
Covalent Bonds
Electrons are shared
Bond between non-metal and non-metal.
Each atom fills up its outermost energy level

11. 2.2 Energy Ability to do work
Conversion of energy from one form to another.
Chemical Energy
Mechanical Energy
Thermal Energy

12. Chapter 2 Energy and Matter States of Matter
Addition of energy to a substance can cause its state to change from a solid to a liquid and from a liquid to a gas.

13. Energy & Chemical Reactions
Chem. Rx: One or more substances change to produce one or more different substances.
Always involves change in energy
Making or breaking chem. bonds

14. Chem. Rx. in capillaries
CO2 + H2O H2CO3
Reactants Products

15. 2 Types of Chem. Rx.
Endothermic (Energy absorbed)
Exothermic (Energy released)

16. Chapter 2
Exothermic
Cellular respiration
Endothermic
Photosynthesis

17. Activation energy:
Energy needed to start a
chemical reaction.
Reaction rate: How quickly the reactants turn into products.
Reaction rate depends on:
Temp
Surface area
Concentration
Catalysts

18. Catalysts:
Reduces the amt. of activation energy that is needed for a reaction to take place.
Enzymes:
Proteins that act as catalysts in living cells.
Factors affecting enzyme activity
Heat, Acidity, Concentration

20. 2.3 Water and Solutions
All Chem. Rx. take place in the cell in solution.
Water molecule: Polar
Allows it to dissolve polar substances (like sugars, ionic cmpds)
“Like dissolves Like”
Water is considered to be a polar molecule due to an uneven distribution of charge.
The electrons in a water molecule are shared unevenly between hydrogen and oxygen.

21. Hydrogen Bonding
Force of attraction between H (+) charge & (-) charge on another atom or molecule.

22. Chapter 2 Hydrogen Bonding
Water and Solutions
Chapter 2
Hydrogen Bonding
A hydrogen bond is the force of attraction between a hydrogen molecule with a partial positive charge and another atom or molecule with a partial or full negative charge.

23. Acids & Bases Water ionizes into: Neutral: (H3O+) = (OH-)
Hydronium ions (H3O+)
Hydroxide ions (OH-)
Neutral: (H3O+) = (OH-)
Acids: Contains more (H3O+) ions
Bases: Contains more (OH-) ions

24. Water and Solutions
Chapter 2
The pH Scale
A scale for comparing the relative concentrations of hydronium ions and hydroxide ions in a solution.
Ranges from 0 to 14.