THE NATURE OF MATTER SECTION 2-1

 TURN TO PAGE 34 IN YOUR BOOK AND WE WILL READ THE CAPTION UNDER THE PICTURE ON THAT PAGE.

 BIOCHEMISTRY: THE STUDY OF THE CHEMICALS OF LIVING THINGS AND THE CHANGES THAT THOSE CHEMICALS UNDERGO—THE CHEMISTRY OF LIFE!

 LIFE DEPENDS ON CHEMISTRY—FOODS YOU EAT AND OXYGEN YOU INHALE ARE USED BY YOUR BODY IN CHEMICAL REACTIONS TO KEEP YOU ALIVE.

 ATOM—THE BASIC UNIT OF LIFE,  ATOMS ARE INCREDIBLY SMALL. HOWEVER THEY CONTAIN SUBATOMIC PARTICLES.  THE SUBATOMIC PARTICLES ARE PROTONS, NEUTRONS, AND ELECTRONS. PG. 35 PLEASE.

 Neutron, and electrons.

 PROTONS HAVE A POSITIVE CHARGE AND NEUTRONS ARE NEUTRAL (NO CHARGE). THEY ARE FOUND IN THE CENTER OF THE ATOM (THE NUCLEUS)  THE ELECTRON IS NEGATIVELY CHARGED AND THEY ARE IN CONSTANT MOTION AROUND THE NUCLEUS. ATOMS ARE NEUTRAL (NO CHARGE ON THE ENTIRE ATOM).

MOTION AROUND THE NUCLEUS OF THE ATOM.

 CHEMICAL ELEMENT—A PURE SUBSTANCE THAT CONSISTS ENTIRELY OF ONE TYPE OF ATOM.  MORE THAN 100 ARE KNOWN TO MAN.  THE PERIODIC TABLE SHOWS THE ELEMENTS.  GO TO APPENDIX G PLEASE.

ISOTOPES  AN ISOTOPE IS AN ELMENT (ATOM) WITH DIFFERENT NUMBERS OF NEUTRONS.  LETS LOOK AT CARBON AS AN EXAMPLE.  THERE IS CARBON-12, CARBON-13, CARBIB-14 PAGE 36 PLEASE.  BECAUSE THEY HAVE THE SAME NUMBER OF ELECTRONS, ALL ISOTOPES OF AN ELEMENT HAVE THE SAME CHEMICAL PROPERTIES.

 SOME ISOTOPES ARE RADIOACTIVE—THE GIVE OFF RADIOACTIVE PARTICLES AND CAN BE DANGEROUS.  HOWEVER THEY CAN BE USEFUL TO TREAT CANCER, KILL BACTERIA, AND FIND THE AGE OF FOSSILS.

CHEMICAL COMPOUNDS  COMPOUND—A SUBSTANCE FORMED BY THE CHEMICAL COMBINATION OF TWO OR MORE ELEMENTS.  WATER AND COMMON SALT ARE COMPOUNDS,  NaCl is salt and H2O is water.  THE ATOMS ARE HELD TOGETHER BY CHEMICAL BONDS (FORCES)

CHEMICAL BONDS  CHEMICAL BONDS (FORCES) HOLD ATOMS TOGETHER TO MAKE COMPOUNDS.  IONIC BONDS - THESE BONDS ARE FORMED WHEN ONE OR MORE ELECTRONS ARE TRANSFERRED FROM ONE ATOM TO ANOTHER.  PAGE 38 PLEASE

 COVALENT BONDS– THIS BOND FORMS WHEN ELECTRONS ARE SHARED BETWEEN ATOMS.  THE COMPOUND FORMED IS CALLED A MOLECULE.  WATER IS AN EXAMPLE  PAGE 38 PLEASE.  THE MOLECULE IS THE SMALLEST UNIT OF MOST COMPOUNDS.

 SOME MOLELCULES ARE ATTRACTED TO OTHER MOLECULES BECAUSE OF THE STREGENTH OF THE ATOMS IN THE MOLECULE.  THIS IS CALLED van der Waals FORCES.  SEE PAGE 39.