1. Chapter 2 Chemical Foundations of Life

2. 2.1 The Building Blocks

3. Matter Atoms are the smallest unit of matter
Atoms cannot be broken down chemically
Different atoms are called elements
Each element has a unique atomic number which is its number of protons

6. Parts of an atom
Nucleus contain protons and neutrons – both contribute to the atoms mass
Changing the number of neutrons changes the mass but not the elements properties
Different masses of the same element are called isotopes.
Some isotopes (radioisotopes) are unstable and break down (decay) into other elements
Some radioisotopes are useful to investigate chemical processes other are used to determine the age of certain materials

7. Electrons
Electrons are negative particles which reside in regions outside of the nucleus.
Adding or removing electrons makes the atom an ion which can positive or negative.
Whether an element gains or loses electrons determines its chemical properties.

9. Bonding
Positive ions form when an atom transfers electrons to another atom.
These oppositely charged atom attract forming a ionic bond.
Some elements don’t transfer but share their elections with other atoms creating a covalent bond.
Unevenly shared electrons makes bonds polar giving it slightly positive and negative “pole”

11. 2.2 Water

12. Water as a solvent
The polarity of individual water molecules attracts them to one another
This type of interaction is called a hydrogen bond
Nonpolar molecules (like oils) do not form H- bonds and do not mix well with water.

14. Water stabilizes temperature
Because of hydrogen bonding, it takes a lot heat to raise the temperature of water (high heat capacity)
Water absorbs heat when it evaporates and releases heat when it is condenses
When water freezes, the molecules lose energy and spread apart

16. Water and pH
Water spontaneously separate into hydrogen ions (H+) and hydroxide ions (OH–)
Water has equal concentrations amounts of H+ and OH-
pH: measure of the hydrogen ions in a solution
Base: accepts hydrogen ions in water
pH above 7
Acid: releases hydrogen ions in water
pH below 7

18. 2.3 Carbon

19. Carbon forms 4 covalent bonds
Organic compounds - chains or rings or carbon and hydrogen.
Wide variety of compounds:
Methane – one carbon
Octane – in gasoline
Beneze – ring of 6 carbons
Buckminster Fullerene – 60 carbon sphere

20. Functional Groups
Additional elements (mostly oxygen and nitrogen) create wider variety of organic compounds
Alcohols
Aldehydes
Amines
Ester