Transcript Unit 1

Unit 1
Basic Chemistry
Watching Youtube Videos


When you click on the video it will play within
the power point
Once you’ve viewed the video you must click
somewhere on the slide outside of the video
box to advance to the next slide
Scientific
Method
Scientific Method


Is the process employed by scientist to
support or reject an idea, by accumulating
data, and testing the data under conditions
which are controlled in ways to give credible
results.
If an idea or hypothesis withstands
substantial independent testing it becomes a
theory, then a law or principle.
Scientific Method


This site has a nice explanation and a quiz
for you to test yourself
http://www.biology4kids.com/files/studies_sci
method.html
States Of Matter



SolidDefinite shape
and volume.
LiquidTakes shape of
container; definite
volume.
GasTakes shape of
container.
(compressible).
Properties

PhysicalWhat a substance is.
 Color, density, odor, solubility in water.


DensityWeight per unit volume.
ChemicalWhat a substance does
 +/- Reactivity with water or air.
 +/- Burning in a flame.
Physical vs Chemical Changes

Physical change: Although some extensive
properties (like shape, phase, etc.) of the
material change, the material itself is the same
before and after the change. The change can
be “undone.”
Ice melting is an example of
a physical change

Chemical change: The atoms have been
altered. What was there at the beginning is
no longer the same. Chemical changes
cannot be undone.
Steel rusting is an example of a
chemical change
Energy


Kinetic Energy
The energy of motion


Potential Energy
Stored energy
Conservation Laws


Matter is neither
created or destroyed,
only arranged from one
form to another.
Energy is neither
created or destroyed,
only changed from one
form to another.

PotentialKineticHeat.
http://www.youtube.com/v/dExpJAECSL8&playnext_from=TL&videos=PAn7NmYhHVw
Elements






Substances which cannot be broken into
simpler substances by ordinary means.
Are homogeneous in compositionthe same
throughout.
Each element represented by a symbol.
O = Oxygen
C = Carbon
AU = Gold.
Periodic Table
Another version at http://www.ptable.com/
Atomic Structure


Atoms are electrically
neutral
Composed of protons,
neutrons & electrons
The Nucleus of the Atom









Protons
Positive charge
Number of protons is the
atomic #
All atoms of same element
have same atomic #
Neutron
No charge ie neutral
Same mass as a proton
located in nucleus
Number of protons +
neutrons = atomic weight
Number of Protons
Number of Protons + Neutrons
Isotopes

Different # of neutrons than normal, i.e.,
different atomic weight.
Normal Carbon
6 protons + 6 neutrons
Atomic Mass = 12
Carbon 14 Isotope
6 protons + 8 neutrons
Atomic Mass = 14
Electrons









1/1837, the mass of a proton
orbit the nucleus
Directly involved in chemical reactions
Determines the chemical property of the atom
Negative charge
Equal in number to the number of protons
Arranged in energy levels or shells around nucleus;
1st shell holds two—all others hold eight
Happiness is a full outer shell 
Atomic Structure
Electron Arrangement




Arranged in energy levels or shells around
nucleus;
1st shell holds two—all others hold eight
Happiness is a full outer shell 
Atoms will share, give away or pick up
electrons to achieve a full outer shell
Electron Arrangement

For example: Carbon

Atomic Number 6, Atomic Mass 12






This tells us there are 6 protons (atomic number)
6 neutrons (atomic mass – atomic number)
And 6 electrons (equal to the number of protons)
The first shell holds a maximum of 2
The other 4 will be in the second shell
So Carbon has 4 electrons in its outer shell
Electron Arrangement

For example: Cobalt (Co)

Atomic Number 27, Atomic Mass 58.93 (round up to 59)








This tells us there are 27 protons (atomic number)
32 neutrons (atomic mass – atomic number)
And 27 electrons (equal to the number of protons)
2 in the first shell
Remember all other shells hold a maximum of 8
8 in the second, 8 in the third, 8 in the fourth
We still have one left so that 1 electron is in the fifth
Cobalt has 1 electron in its outer shell
Electron Arrangement
Cobalt
27 Protons
32 Neutrons
27 Electrons
2 in the first shell
8 in shells 2, 3, and 4
1 in shell 5
electrons
Protons and Neutrons
In the nucleus
Electron Arrangement

Now would be a good time for you to work on
the Periodic Table Assignment! 
Atomic Bonding




Ionic Bonding
Results from the
transfer of electrons
Atoms gain/lose
electrons.
Results in ions


Atom with a charge.
The charge difference
holds the resulting
molecule together
http://www.youtube.com/v/xTx_DWboEVs&playnext_from=TL&videos=Prgzu17ouAM
Atomic Bonding





Covalent Bonding
Results from a sharing of
electrons b/t two atoms.
Each atom provide an
electron
The Shared electron pair
orbits both nuclei this is
what keeps the molecule
together
Larger nuclei will hog the
shared electrons from
smaller nuclei
http://www.youtube.com/v/1wpDicW_MQQ&playnext_from=TL&videos=tqqVAiDEMWo
Atomic Bonding







Hydrogen Bond
Special bond—very weak
Bond between molecules NOT
between atoms
Results from a covalent bond
involving hydrogen
Shared electron spends more time
around the bigger nucleus of the
Oxygen atom
This leaves the hydrogen end with a
net positive charge & the Oxygen
end with a net negative.
A polar molecule due to the charge
difference from one end of the
molecule to the other.
Covalent Bond
Between Oxygen and
Hydrogen
Between two
Water molecules
Compounds





Combination of elements.
Can be separated into their parts by chemical means.
Homogeneous in composition.
Definite composition
Have different properties than their parts
 Example: Oxygen +Hydrogen= H2O water.
 Oxygen and Hydrogen at room temperature are gasses
 Neither conduct electricity
 Water is a liquid at room temperature and does conduct electricity
Mixture





Combination of substances
Can be separated by physical means
No set composition
Heterogeneous in composition
Parts retain their own character


Example: Italian Salad Dressing
The vinegar and oil can be mixed together with
spices but they can be separated from one
another
Macromolecules: Proteins


Compound of amino acids joined together.
Each protein has a definite structure.



Primary—linear sequence of amino acids
Secondary-Initial folding to sequester
hydrophobic
(water hating) amino acids.



Alpha Helix
Beta Pleated Sheet
Tertiary—Complex folding to created final 3D
shape
Macromolecules: Proteins
Protein Structure
http://www.youtube.com/v/lijQ3a8yUYQ
Macromolecules: Proteins

Denaturation




To destroy the shape of a protein
Heat, ph, salt concentrate on
Maybe reversible or not
Cook an egg: the heat denatures the albumin
protein in egg white
Macromolecules: Carbohydrates






Carbohydrates
Sugars, Starches, Cellulose
All contain carbon, hydrogen, & oxygen in
a 1:2:1 ratio
Glucose C6H12O6
Monosaccharide: Single Sugar, glucose.
Disacharide: Double Sugar, sucrose
Macromolecules: Carbohydrates





Polysacharride :
Many sugar molecules joined together
Starch
 Plant form of energy storage.
 Insoluble in water.
 Digestible by animals.
 Detected by iodine.
Celluose
 wood, cotton, paper;
 insoluble in water;
 not digestible by animals.
Glycogen
 Animal form of energy storage
Macromolecules: Nucleic Acids








Information storage
DNA: DeoxyriboNucleic
Acid)
Organism’s instructions for
assembly
Double stranded
Located in nucleus
BASES
Adenine
Guanine
Thymine Cytosine
Macromolecules: Nucleic Acids





RNA: RiboNucleic Acid
Information Use, daily
operation of organism.
Single stranded
Made in nucleus, exported
for work throughout cell
BASES


Adenine Guanine
Uracil Cytosine
Macromolecules: Lipids / Fats




Insoluble in water.
Combination of fatty acids and glycerol.
Reserve energy storage.
Make up cell membranes and some
hormones
Macromolecules: Lipids / Fats





Saturated
All carbon atoms linked by
single bond.
“Saturated with hydrogen”
Solid at room temp
Most of the animal fats

responsible for increasing
the amount of cholesterol




Unsaturated
At least one double
bond between 1 pair of
carbon atoms.
Liquid at room
temperature
Most vegetable fats
Enzymes







Biological catalyst.
Increases the rate of
chemical reaction.
Lowers the activation
energy required for
reaction.
All enzymes are proteins.
Have specific active site to
bind to substrates.
These active sites are
created by the 3D structure
of the protein.
What would you expect if an
enzyme was subjected to
extreme heat?
http://www.youtube.com/v/V4OPO6JQLOE&playnext_from=TL&videos=I91ovDgWCys
Acids





Donate H+ ions to solution
Can be in solid or liquid form
Sour taste
The more H+ ions released the stronger the acid
Common Acids




HCl Hydrochloric (in stomach)
H2SO4 Sulfuric (battery acid)
HNO3
Nitric (Medical Testing)
H2CO3 Carbonic (Soda)
Bases




Donate OH-, hydroxide ions to solution
Slippery feel
Bitter taste
Common Bases



NaOH Sodium Hydroxide (Drain cleaner)
NH4OH Ammonium Hydroxide (Cleaning)
NH3 Ammonia (Cleaning)
pH Scale







A measure of the H+ ion concentration in a solution.
Each whole number change in PH value is a 10 fold
d/f in H+ concentration
pH Scale 0-14
<7 is acid
=7 is neutral
>7 is base
The farther away from 7 the stronger the acid or
base
pH Scale
http://www.youtube.com/v/gwFR_Iph5R0
Indicators and Buffers

Indicators



Compounds which look
different according to the pH
pH paper; litmus paper.
Phenolphalein, bromthymol
Blue.
All change color in
response to pH




Buffers
Compounds which
resist changes in PH
serve as reservoir for
H+ ions.
Can donate or accept
H+ ions
Very important in
maintaining
homeostasis in living
organisms
CHEMICAL REACTIONS

Dehydration Synthesis
 Synthesis: to make
 A+B  C

In the animation notice
the water molecule
bouncing away from the
sucrose
http://www.youtube.com/v/UyDnnD3fMaU&feature=PlayList&p=5DD6329BBE0DE93F&playnext_from=PL&playnext=1&index=1
CHEMICAL REACTIONS
H2O



Hydrolysis
to split apart using
water
The water wedges itself
against the A-B bond
until it breaks
B
A
A
+
B
Metabolism



We use both hydrolysis & dehydration
synthesis
Hydrolysis breaks down the food we eat.
Dehydration synthesis builds what our bodies
need