CHEMISTRY For DUMMIES

(you’re not dummies)

This is just a dumb lecture.

Chapter 2

What you were supposed to learn in ICS or Chemistry last year.

Everything in the universe is made of matter.But what is MATTER?

THE ATOM IS THE BASIC UNIT OF MATTER

Nucleus contains:PROTON: (+) & 1 AMUNEUTRON: neutral & 1 AMU

Outside the nucleus:ELECTRON: (-) & no AMU

ATOM = The Dodger’s StadiumNUCLEUS = baseball (pencil eraser) on the pitcher’s mound (contains protons & electrons)ELECTRONS = seating… even nose-bleed seats

The periodic table of elements shows all the types of matter known to man.

ELEMENTS are pure substances that cannot be broken chemically into simpler kinds of matter.

Each square shows the:

chemical symbol,atomic number, & atomic mass.

Ex. Carbon is C6

12Atomic # =‘s # of protons # of electrons

Atomic mass = protons + neutrons

CarbonHydrogenNitrogenOxygenPhosphorusSulfur

Biology is cool because we don’t need to memorize all100+ elements… we only need to be concerned with The 6 chemicals of LIFE… (What you need to live.)

• The ATOM is the smallest unit of matter.

• All atoms are basically the same:1. protons (+) & neutrons (no charge)

IN NUCLEUS2. electrons (-) OUTSIDE the NUCLEUS3. NEUTRAL OVERALL (#p=#e)4. When atoms gain or lose electrons

they become IONS- they have a charge.

Ex. a Hydrogen atom that loses it’s electron is called a hydrogen ion, H+, or a proton.

SUMMARY:

CHEMISTRY IS THE STUDY OF THE BEHAVIOR OF ATOMS… OF

MATTER.WHAT HAVE CHEMISTS LEARNED???

1. The nature of most atoms is that they are LONELY and sometimes AGGRESSIVE!

2. Most atoms team up with or overtake other atoms in an attempt to get the “right” number of electrons. This is how molecules are formed.

3. Only the NOBLE GASSES can exist on their own.4. ATOMS will switch partners when provoked. This is

what chemical reactions are all about.5. Don’t mess with an atom’s nucleus.

Sort of like psychology- but for atoms.

MATTER EXISTS IN DIFFERENT FORMS DEPENDING ON ITS OWN PERSONALITY AND ITS ENVIRONMENT.

See above: States of Matter… Temperature can influence this.

one column of elementsis NONREACTIVE(noble gasses).

The rest stick together through variousKinds of bonds… and so we Have “matter” that is big enough to see.

COMPOUNDex. water, salt- NaCl, glucose

Pure substance that is made

up of atoms of two or more

elements.Water molecules

MOLECULE Ex. oxygen (O2)

the simplest part of a substance

that retainsall the properties of the substance and that can exist

in a free state.Water, glucose, carbon dioxide etc.

Oxygen gas is a molecule but not a Compound because it is only made fromone kind of element… two oxygen atoms Are held together through a double bond.

BONDING… 2 BASIC TYPES OF BONDS.

COVALENT BOND

Atoms share theirelectrons to reach the

MAGIC NUMBER2 or 8.

Both hydrogensare sharing theirone electron so bothnow have two.

THIS IS HOW HYROGENGAS EXISTS IN NATURE.

2 TYPES OF COVALENT BONDS:

Nonpolar covalent bond- electrons are shared equally because both atoms have an equal pull on the electrons.

Ex. Oxygen O=O or Hydrogen H-H

Polar covalent bond- electrons are NOT shared equally because one atom is more electronegative than the other.

Ex. Water H-O-H

IONIC BOND

Electrons are exchanged.

Both become IONSOpposites attract!

Ex. Chlorine STEALS anElectron from Sodium.

Na+ Cl-

GAIN OR LOSE ELECTRONS…

Gaining an electronMakes the atom aNegative ion w/ a Charge of -1(anion)

Losing an electron Makes the atomA positive ion w/ a Charge of +1(cation)

CHEMICAL REACTIONS… what are they?

• SIMPLY PUT… they are atoms switching groups or clique’s.

• Bonds get broken.• Bonds are formed.

• Rxns can release or require energy.

6CO2 + 6H20 + light C6H12O6 + 6O2

Chem rxn for photosynthesis:

EXERGONIC Rxns RELEASE ENERGYex. burning a candle or cell respiration

ENDERGONIC Rxns. REQUIRE ENERGYex. Photosynthesis.

ACTIVATION ENERGY

Amount of energy needed to start a spontaneous chemical reaction.

HERE’S A REACTION WITH A HELPER… A CATALYST lowers the amount of activationenergy needed to start a reaction .ENZYMES are biological catalyst.

SOLUTIONS are easy to understand…

• Solute = kool-aid

• Solvent = water

• Solution = drink

Cell contents are solutions… so is your blood

SOLVENT = water

SOLUTES=

glucose, ions like Cl-, Ca+, Na+, H+

Urea (cell waste), proteins, hormones

The pH scale is a scale showing the relative amounts of (H+) Hydrogen and (OH-) Hydroxide

ions in a solution.

The pHof a solutionwill influencethe shape ofproteins in thatsolution