CHEMISTRY OF LIF

the basics

• Every living and nonliving things is

made up of matter

• MATTER: anything that has mass &

takes up space

What does all matter have in common?

• Smallest unit of matter – ALL matter is made of

particles called atoms

• Always in motion and bumping into each other – Kinetic energy – the

energy of motion

• Have a definite shape & volume

• Molecules are packed tightly together

in a pattern

• DO move – more of a vibration

• Have a definite volume but NO

definite shape

– Not in any arrangement

• Molecules are loosely packed and

flow against each other

– loosey goosey = loosey liquids

• Have no definite shape and no

definite volume

– Not in any arrangement

• Molecules are far apart and can move

freely

Matter either looses or absorbs energy when it changes states

• Solid liquid = melting

• Solid gas = sublimation

• Liquid solid = freezing

• Liquid gas = vaporization

• Gas liquid = condensation

• Gas solid = deposition

• Two major parts

– Nucleus

• Positively charged

– Electron cloud • Negatively

charged

• Proton – Positively charged

– Found in nucleus

– The # of these determines the elements

– Contributes to mass

• Neutrons – No charge – neutral

– Found in nucleus

– Contributes to mass

+ o

• Electron

– Negatively charges

– Located in electron

cloud

– So small contribute

very little mass

– The outer most

electrons are used

in bonding

(valence electrons)

• A substance made up of atoms that all

have the same number of protons

• CAN NOT be broken down into simpler

substances

– EX: Gold & Oxygen

• Arrangement of elements ordered

by:

–Atomic number

–Electron configuration

–Chemical properties

• Element name – Unique for each element

– Usually from Latin based words due to ancient Romans attempting to identify elements

– Sometimes named after scientists who discovered them (ego much?) • Must be approved by committee

• Element symbol – Some names are longggg or hard to

pronounce

– Some based on name of element others are based in different language

– First letter is ALWAYS capitalized

12

24.305

Magnesium

Mg

• Atomic number – The number of protons found in

the nucleus

• Atomic mass – The total mass of all the protons

& neutrons • Each proton & each neutron are

equal to 1 AMU (atomic mass unit

atomic mass – atomic number = # of neutrons

12

24.305

Magnesium

Mg

• Contain only one type of atom

• Cannot be broken down into simpler substance by any physical or chemical means

• Can exist as atoms or molecules

Sodium (Na)

• Contain atoms or 2 or more different elements

• Bonded together in a specific pattern

• Can be broken down by chemical means but not physical means

• Has different properties than its components

Sodium Chloride

(NaCl)

• Contains 2 or more substances (elements or compounds) that are NOT bonded together

• Can be separated physically

• Retains many of the same properties of its components

Salt Water (NaCl + H2O)

• The outer most electrons that are used

in bonding

• Determine the reactivity of an atom

– Reactivity = how likely an atom is to bond

with another atom

– Can use periodic table to determine

reactivity

• Strongest of chemical bonds

• Formed by the attraction between two oppositely charged ions – Ion = atom that has lost or gained an election

causing it to have a charge

• Valence electrons are stolen or taken

• Strong bond

• Sharing of electrons between atoms – Makes the outer shell of electron cloud

“feel” full

• A very weak bond

• Between molecules – not atoms!

• Between partial negative region of one molecule and a positive region of another

• WATER!!!

since we’re talking about hydrogen bonds….

…

• Nearly 70% of your body is made of water

• Water is where most cellular events take place

• Water helps move nutrients and other substances into and out of your cells

So…. It’s kind of important!

• Heat – Stores heat efficiently

– Heats more slowly and stores heat longer than most substances

– This allows our bodies to maintain a constant state

• Water bonds to itself and other substances

• Cohesion

– Hydrogen bonds between water molecules cause an attraction to each other

– Allows water to form drops and thin films

– Also causes surface tension – prevents water surface from stretching or breaking easily

• Adhesion

– Water molecules are also attracted to

other substances

• Universal solvent – Many substances dissolve in water making

solutions because of polarity • Solution = a mixture in which one or more

substances are evenly distributed in another substance

– Non-polar molecules DO NOT dissolve in water • EX: oil and water

• When solutions are made with water

as a solvent it may add or reduce

hydrogen ions

• This determines the acidity or alkalinity

of a solution

• Acids

– Compounds that form hydrogen ions

when dissolved in water

• Bases

– Compounds that reduce the

concentration of hydrogen ions when

dissolved in water

Measures the acidity or alkalinity of a substance

sounds scary but… it’s not!

• A process that involves the rearrangement of the molecular or ionic structure of a substance

• Six different types – Combustion

– Neutralization

– Synthesis – Decomposition

– Single displacement

– Double displacement

• During chemical reactions, energy is

both absorbed and released.

– Some absorb more than they release and

others release more than they absorb

• Some energy must be absorbed to

start a chemical reaction = activation

energy

• Endothermic: a chemical reaction that

absorbs more energy than it releases

• Exothermic: a chemical reaction that

releases more energy than it absorbs

Carefully rinse and dry off the thermometer

Carefully dump out the contents in the test tube down the sink. Rinse out all materials. Carefully and to your best ability dry it.

Rinse your test tube rack off. Place the clean test tube back.

Carefully remove the beaker from the hot plate. Dump the water into the sink.

Rinse the beaker and dry it off. Place it back on the hot plate when you’re done.

Rinse your graduated cylinder and dry them out to the best of your ability.

• Occurs when a compound containing

carbon and hydrogen reacts with

oxygen

• Creates water vapor, carbon dioxide,

and heat

CH4 2 O2 CO2 2 H2O

methane oxygen carbon dioxide water

• Happens when an acid and a base

are added to each other

• Complete neutralization occurs if the

same amount of hydrogen and

hydroxide ions are present and salt

and water are formed

HCl NaOH NaCl H2O hydrogen chloride sodium hydroxide sodium chloride water

• Occurs when simple compounds

combine to make a more complex

compound

2 Na Cl2 2 NaCl

• Occurs when a compound or

molecule breaks down into simpler

ones

2 H2O2 2 H2O O2

• Occurs when a pure element switches

places with an element in a

compound

Mg 2 HCl H2 MgCl2

• Occurs when the cations of two

compounds switch to form new

compounds

HCl AgNO2 AgCl HNO2

• Color change

• Gas production

• Light emission

• Odor

• Precipitates

• Temperature change

• Symbolic representation of a chemical

reaction

• Uses symbols and chemical formulas

– Chemical formulas represent a molecule

using the element symbols and numbers

• EX: CO2

A chemical equation has three sections

– Reactants

– Products

– Yield

( ) ( ) The stuff that goes into

the reaction

The stuff that comes out

of the reaction

YIELD

6 CO2 + 6 H2O C6H12O6 + 6 O2

• Subscript

– shows the number of atoms for that

element

• Coefficient

– Shows the number of molecules

6 CO2 + 6 H2O C6H12O6 + 6 O2

1. Identify and count the number of each element in the equation

2. The goal is to have an equal number of atoms for each element on both sides

- We use multiplication

Let’s give it a try…

This one is easy!

6 CO2 + 6 H2O C6H12O6 + 6 O2

reactants products

Let’s try another one

Na2 + F2 NaF2

reactants products

Balancing Chemical Equations

Worksheet

• Law of Conservation of Mass

– Mass cannot be created or destroyed

• Law of Conservation of Matter

– Matter cannot be created or destroyed

but it can change forms