Name __________
Date _____Per ___
Chapter 2
The Chemistry of Life
Biology
Mr. Rizzo
2-1 The Nature of Matter
Atoms
Electron
ATOMS
 The small units of matter
 2 major Parts
o Nucleus (Protons+Neutrons)
o Electrons
 Atoms are smaller than cells
Structure of an atom
Electron
Cloud
Nucleus
Nucleus
+Found in the center of an atom.
+Contains :
protons (+ charge)
neutrons (neutral charge)
+The nucleus has an overall positive charge(+).
Electron Cloud (shells)
--Found outside of the nucleus.
--Made solely of electrons
--Has a negative charge(-).
2-3 Carbon Compounds
er
Anything that has mass and takes up space (volume).
All matter is made up of atoms.
Elements
Pure substances made up of only one type of atom
106 known kinds (roughly)
Examples of elements;
Gold
Hydrogen
Carbon
COMPOUNDS
 A COMBINATION OF DIFFERENT ELEMENTS
 THEY ARE MADE UP OF 2 OR MORE DIFFERENT KINDS OF ATOMS
 EXAMPLES: CO2, H2O, & C6 H12O6
Atomic Number
The number of protons found in an Atom AKA the proton number
Helps you locate an element on the periodic table.
Important Elements in Biology
Atomic weight
The weight of the nucleus.
The mass of the neutrons and protons of an atom.
AMU (Atomic mass units)
Inorganic Compounds
> Any compound that does not contain the elements carbon and hydrogen is
inorganic.
> Examples:
> carbon dioxide
> calcium carbonate
> water
> salts
> Phosphates
> bases and certain acids
2. Helium
A Chlorine Atom
Sodium Atom
Ions and Isotope
A Chlorine ion
A Sodium ION
pH: pH is the ratio of H+ (hydrogen) and OH- (Hydroxide) ions. When both
are in equal concentration in pure water, it has a pH of 7.0
 Acidic Solution: an excess of H+ ions, the water has a pH less then 7.
 Basic Solution: an excess of OH- ions, the water has a pH above 7.
 Optimal 8.2 depending, but always over 8
 Remember: The pH scale: (What can we use to test for pH???????)