BASIC CHEMISTRY

BASIC CHEMISTRY• ATOMS, ELEMENTS, AND COMPOUNDS

– ATOM• SMALLEST UNIT OF MATTER• CAN NOT BE BROKEN DOWN

BY ANY ORDINARY CHEMICALMEANS

• ONLY ABOUT 100 KINDS OFATOMS

– ELEMENTS• SUBSTANCES MADE OF ONLY

ONE KIND OF ATOM– COMPOUNDS

• TWO OR MORE DIFFERENTKINDS OF ATOMS ARE COMBINED

BASIC CHEMISTRY

BASIC CHEMISTRY

• MAJOR ELEMENTS FOR BIOLOGY

BASIC CHEMISTRY

• STRUCTURE OF ATOMS– SUB-ATOMIC PARTICLES• PROTONS• NEUTRONS• ELECTRONS

– ATOMIC MODEL• INACCURATE, BUT

HELPS US BESTUNDERSTAND THINGS• ATOMIC NUCLEUS &

ELECTRON ORBITALS

BASIC CHEMISTRY

• STRUCTURE OF ATOMS– ATOMIC NUMBER• # OF PROTONS

– ATOMIC MASS• # OF PROTONS

+# OF NEUTRONS

BASIC CHEMISTRY

• STRUCTURE OF ATOMS– ISOTOPES• ATOMS THAT DIFFER

ONLY BY THE # OFNEUTRONS• SAME ATOMIC #,

DIFFERENT ATOMICMASS

BASIC CHEMISTRY

• RADIOACTIVE ISOTOPES– MANY ISOTOPES ARE UNSTABLE, AND SLOWLY

BREAKDOWN– THE EMISSION OF PARTICLES

DURING THIS BREAKDOWN IS CALLED RADIOACTIVITY

– SCIENCE USES THIS PROCESS FOR HELPFUL TOOLS; RADIOACTIVE DATING (CARBON DATING), RADIOACTIVE DIAGNOSIS, RADIATION THERAPY, ETC.

BASIC CHEMISTRY

• STRUCTURE OF ATOMS– ELECTRONS• NORMALLY, ATOMS

HAVE THE SAME# OF ELECTRONS ASPROTONS• THEREFORE,

(+) = (-) SO THE ATOMIS NEUTRAL• ELECTRON SHELLS

BASIC CHEMISTRY

• STRUCTURE OF ATOMS– ELECTRON SHELLS

• A.K.AVALENCE SHELLS

• ATOMS ARE “HAPPIEST”WHEN THEIRELECTRON SHELLS AREFILLED

• ELECTRONS DON’TEXIST ALONE, SOWHERE ARE THEREMORE TO FIND TOFILL SHELLS???

BASIC CHEMISTRY

• CHEMICAL BONDING– THE FORCE THAT HOLDS ATOMS TOGETHER– TWO MAJOR TYPES– COVALENT BONDING

VS. IONIC BONDING

BASIC CHEMISTRY

• COVALENT BONDING– CHEMICAL BOND THAT

RESULTS FROM THE SHARING OF ELECTRONS

– ALWAYS RESULTS IN A MOLECULE• TWO OR MORE ATOMS

COMBINE AND ACT AS A SINGLE PARTICLE

BASIC CHEMISTRY

• IONIC BONDING– CHEMICAL BOND THAT

RESULTS FROM THE TRANSFER OF ELECTRONS BETWEEN ATOMS

– RESULTS FROM THE FORMATION OF IONS• AN ATOM THAT HAS LOST

OR GAINED ELECTRONS, GIVING IT EXCESS ELECTRIC CHARGE

BASIC CHEMISTRY

• CHEMICAL FORMULA VS. STRUCTURAL FORMULA

BASIC CHEMISTRY

• CHEMICAL REACTIONS– THE FORMATION OF DIFFERENT SUBSTANCES

FROM THE COMBINATION OF EXISTING ATOMS (MOLECULES)

– REACTANTS VS. PRODUCTS

– *LAW OFCONSERVATION OFMASS*

BASIC CHEMISTRY

• CHEMICAL REACTIONS– UNBALANCED VS. BALANCED EQUATIONS

BASIC CHEMISTRY

• CHEMICAL COMPOUNDS VS MIXTURES– COMPOUNDS

• ATOMS, OR IONS, ARE JOINED TOGETHER BY A CHEMICAL BOND

– MIXTURES• SUBSTANCES ARE

PHYSICALLY COMBINED (OR MIXED) WITHOUT FORMING A NEW CHEMICAL BOND

BASIC CHEMISTRY

• MIXTURES– SOLUTIONS VS SUSPENSIONS VS COLLOIDS

BASIC CHEMISTRY

• MIXTURES– SOLUTIONS

• HOMOGENEOUS MIXTURE• SOLUTE + SOLVENT =

SOLUTION• SOLVENT

– THE SUBSTANCE THAT MAKES UP THE BULK OF THE SOLUTION

• SOLUTE– SUBSTANCES DISSOLVED

IN THE SOLVENT

• SUSPENSION– A MIXTURE THAT

SEPARATES

• COLLOIDAL DISPERSIONS– MIXTURE THAT IS “IN-

BETWEEN” A SOLUTION AND SUSPENSION

BASIC CHEMISTRY

• ACIDS, BASES, AND SALTS– SOME OF THE MOST

IMPORTANT COMPOUNDS THAT FORM SPECIAL “SOLUTIONS” WHEN MIXED WITH WATER

• ACID– ANY COMPOUND THAT

PRODUCES [H+] IN SOLUTION

• BASE– ANY COMPOUND THAT

PRODUCES [OH-] IN SOLUTION

BASIC CHEMISTRY

• ACIDS, BASES, AND SALTS– SOME OF THE MOST

IMPORTANT COMPOUNDS THAT FORM SPECIAL “SOLUTIONS” WHEN MIXED WITH WATER

• NEUTRALIZATION– THE PROCESS OF REACTING

AN ACID AND A BASE TO PRODUCE A NEUTRAL SOLUTION

– RESULTS IN WATER AND SALTS

• SALTS– AN IONIC COMPOUND

PRODUCED BY THE NEUTRALIZATION REACTION N BETWEEN ACID AND BASE

BASIC CHEMISTRY

• THE pH SCALE

BASIC CHEMISTRY

• pH SCALE– pH IS THE UNIT WE USE TO MEASURE THE [H+] IN

A SOLUTION– SCALE RANGES FROM 0 – 14 (LOGARITHMIC

SCALE…POWER OF 10)– DIFFERENCE OF 1 pH = 10X DIFFERENCE IN

STRENGTH– BECAUSE WE MEASURE [H+], BASES CAN BE

DEFINED A DIFFERENT WAY!!!

BASIC CHEMISTRY

• pH INDICATORS– SUBSTANCE THAT CHANGES COLOR BASED ON THE

ACIDITY OR BASICITY OF A SOLUTION

BASIC CHEMISTRY

• WHY DO WE CARE SO MUCH ABOUT THESE PARTICULAR SUBSTANCES (ACIDS, BASES, SALTS???)

BASIC CHEMISTRY

• WHAT OTHER CHEMICAL COMPOUNDS ARE ESSENTIAL, OR DIRECTLY EFFECT, LIVING THINGS??

• THAT SHOULD BE THE FOCUS OF OUR NEXT CHAPTER!!!

• OH WAIT…IT IS!!! COME BACK TO FIND OUT MORE