Download Objective 4

Objective 4
The structures and properties of matter
• Review of metric system
Meter= m=
Liter = L=
Grams= g=
Everything
Atoms (Matter)
Chemistry
109 Elements
Energy
Physics
Potential
Kinetic
Chemistry of Life
Only about 25 Elements are
essential to living organisms.
96 % of the human body is;
Carbon, hydrogen, oxygen, and
nitrogen
Your body needs energy provided
by Sugars from Food.
You body undergoes a
series of Chemical
Reactions in which Sugars
are broken down to
Carbon Dioxide and Water
In this process, energy is released for use by
the body. (Breaking Chemical Bonds Releases
Energy)
Matter
Anything that has mass
and takes up space.
*Weight is not mass
it is do to gravity
Energy is NOT matter
Matter is divided into 3 types:
Oxygen
• Elements – simple substances- one type of atom
• Compounds – made of 2 or more elementsdifferent atoms
• Mixtures- two or more substances mixed
together
There are two types of
mixtures:
• Heterogeneous-
mixture is not the
same from place to
place.
– Chocolate chip
cookie, gravel,
soil.
• Homogeneous• same composition
throughout.
-Kool-aid, air, brass
Decide if the substance is
Element, Compound , or Mixture?
1. Water
1. Compound
2. Table Salt
2. Compound
3. Oxygen
3. Element
4. Dirt
4. Mixture
5. Air
5. Mixture/Solution
Click Mouse button to see answers!
STATES OF MATTER
The RATE at which Atoms or Molecules of a Substance MOVE
DETERMINES ITS STATE.
• States of matter
• PHASES• Matter changing form one
state to another
• To cause a Substance to
Change: Thermal Energy
(Heat) must be Added or
Removed
• *melting ice
•
GAS –
• Has NO DEFINITE VOLUME and NO DEFINITE SHAPE.
•
A Gas ALWAYS TAKES BOTH THE VOLUME AND THE
SHAPE OF ANY CONTAINER INTO WHICH IT IS
PLACED.
GAS
NOT
GASOLINE
• SOLID–
• Anything that has BOTH A FIXED VOLUME
and SHAPE.
• Particles of a solid are Tightly linked together
and they Vibrate in Place.
A rock is a solid
–
LIQUID-
Anything that has a FIXED VOLUME
but NO DEFINITE SHAPE.
• Phase diagram
Changes in Matter –
Physical
or
Chemical?
Physical changes
are changes in the state of
matter. They do not change the
substance.
Melting, boiling,
condensing, freezing, cutting
tearing
Chemical changes
are reactions that result
in new products with
new properties
Physical Change
Chemical change
Endothermic Vs Exothermic
reactions
• Endothermic – absorb energy, they can feel cold
•
• Exothermic – gives off energy, the can feel
WATER
Water is perhaps the most important
compound in living organisms.
Water makes up 70 to 95 percent of most
organisms.
Properties of Fluids
Density, Buoyancy, Viscosity
FLUIDSWhen atoms or molecules are free to flow
past each other they are called fluids. Fluids
can be liquids or gases…
Four measurable properties of fluids are:
· Density
· Pressure
· Buoyancy
· Vicosity
Density
The Mass per unit of volume of substance
D=M/V
Cube 1
Cube 2
Which cube is denser?
Both cubes have the same volume, but
Cube 1 has more molecules so it is
denser than the Cube 2!
DENSITY
Water has a density of 1.0 g/mL
Solids are more dense than their
liquids (except water)
Liquids are more dense than their
gases
DENSITY
Measure in:
g/mL for liquid
g/L
for gases
g/cm3 for solid
Density
Density = mass/volume
What is the density of a gold coin with a mass of
32 g and a volume of 1.66 cm3?
D = M/V
= 32 g/1.66 cm3
= 19.3 g/cm3 or 19.3 g/mL
VISCOSITY
Viscosity - is the resistance of a fluid
to flow (it’s thickness)
Syrup has a greater viscosity than water,
it pours slower
Buoyancy
The buoyant force of a liquid
acts upward on a body
placed in it and it is against
the force of gravity.
IT MAKES STUFF FLOAT
• Increasing a fluid's or gases density also increases
it’s buoyant force
• Buoyancy increases as the density of the liquid/
gas increases
The thicker the liquid is
the more it floats “something”
Pressure
Bernoulli’s Principle:
The pressure in a fluid decreases as the
fluid’s velocity increases.
How airplanes fly!
Pascal’s principle
pressure applied to a
fluid in a closed
container is transmitted
equally to every point of
the fluid and the walls
of the container
The of Law Conservation of Mass
Matter is not
created or destroyed
during a chemical reaction
Not going to
happen
Mixture
A mixture is a combination of substances in
which the individual components retain their
own properties.
Think : salad - the things in it can be separated.
Liquids & Gases
Properties of Solutions
A solution is a type of mixture
One substance dissolves another
The substances are evenly mixed
Properties of Solutions
Solvent – the substance that does the dissolving
Solute – the substance dissolved
Concentration – the amount of solute in the solvent
Dilution
– the solution has added solvent.
Saturated - solution contains as much solute as possible
Solute - NaCl (salt)
+
Solvent - H2O (water)
Factors that influence Solubility
The solubility depends on it’s chemical make-up
&
are effected by:
Temperature
Pressure
Nature of solvent
& solute
Water is the “universal
solvent” it’s Polar
Dissolving
A solvent dissolves a solute by surrounding it
and pulling it apart
“Like dissolves like”
oil  oil
water  water
DISSOLVING
If you want to speed it up:
Crush it
Stir it
Heat it
Water has special properties
Cohesion is the tendency of water molecules
to stick together. Cohesion produces surface
tension, which causes a film-like boundary to
form on the surface of water.
Adhesion is the tendency of
water to stick to other polar substances
Water resists temperature changes
water requires more heat to increase its
temperature than do most other common
liquids. (Specific heat)
Water expands when it freezes
• Water is one of the few substances that
expands when it freezes.
• Ice is less dense than liquid water so it floats
Dissolving Gases
• Higher pressure helps dissolve gases in
liquid
• Colder temperatures will help dissolve a gas
* think about a can of soda pop
PROBLEM
A 0.2 g crystal of gypsum dissolves very slowly in 100
mL of water while the water is stirred. Which of these
would cause the gypsum to dissolve faster?
F Decreasing the water
temperature
G Stopping the stirring
H Lowering the air
pressure
J Crushing the crystal
What are the 3 ways to
increase the rate at which
a solid dissolves?
Heat it!
Crush it!
Stir it!
ANSWER?
J
All of these can affect the rate at which a
solid dissolves in water except —
A decreasing air pressure
B stirring the water
C increasing the
temperature of the
water
D using larger crystals of
the solid
• A solubility curve shows
the amount of each solute
that will dissolve in 100g
H20 at each temperature.
• Saturated is on the line.
• Unsaturated is below the
line.
• Supersaturated is above
the line.
Grams solute/100 g H2O
How much solute will
dissolve?
51 At which
temperature
do KBr and
KNO3 have
the same
solubility?
A 27°C
B 48°C
C 65°C
D 80°C
• The pH is a measure of how acidic or basic a solution is.
• A scale with values ranging from below 0 to above 14 is used
to measure pH.
PH SCALE
0 1 2 3
More acidic
4
5
6 7 8
Neutral
9 10
11 12 13 14
More basic
pH is a measure of the
Strength of Acids & Bases
• Litmus turns red in acids and blue in bases
• Phenothalein turns pink in a base and stays clear
in acids.
ACID
BASE
Remember - A begins the
alphabet and zero begins
numbers
•Substances with a pH below 7 are acidic.
An acid is any substance that forms
hydrogen ions (H+) in water.
*taste is sharp and sour
Ex: orange juice and vinegar
Bases = Blue = Big
Substances with a pH above 7 are
basic.
•
A base is any substance that forms
hydroxide ions (OH-) in water.
Ex: soaps and egg whites
A solution is neutral if its pH equals 7.
In a neutral solution the
concentration of hydrogen ions
equals that of hydroxide ions.
Ex: pure water & you
Compounds that yield ions other than
hydrogen or hydroxide ions when in
solution are called salts.
Neutralizing
• Acids and bases react to neutralize each
other.
• Baking soda and vinegar reaction
• End products includes water and salt
Tritration
• Titration is a procedure
used in chemistry in
order to determine the
strength of an acid or a
base
Higher pH levels means?
33 Two clear solutions are placed in separate
beakers. The first solution has a pH of 4, and the pH of
the second solution is unknown. If the two solutions
are mixed and the resulting pH is 5, the second
solution must have —
A fewer suspended solids
B a lower temperature
C more dissolved salt (NaCl) particles
D a higher concentration of OH– ions correct
Solutions are homogeneous and have no suspended solids.
Nothing is mentioned about temperature so B is invalid.
NaCl solutions are neutral so
have no effect on pH.
For Chemical Reactions to begin,
Energy Must Be Added to the
Reactants.
ACTIVATION ENERGY- The Energy
NEEDED to START the Reaction
CATALYSTS -The chemical
substances that starts the reaction or
speeds it up
Electron
shells
Valancee
lectrons
Nucleus(Protons & neutrons)
electrons
Atoms: The Building
Blocks of Elements
•An atom is the smallest particle of an
element that has the characteristics of
that element.
•Atoms are the basic building blocks of
all matter.
Nucleus
Protons
Neutrons
Electron energy levels
Valance Electrons
Atoms
An Atom is made up of:
Nucleus – The center of the atom, it’s made of:
>Protons – heavy, positively charged particles
>Neutrons – heavy, no charge – (act like glue)
Electrons – tiny negative charged particles
that circle the nucleus in shells
Electron Shells
*But only 2 shells concern us
1. Shell one has 2 electrons
2. Fill all shells with up to 8 electrons
3. Valance shell (outermost shell) - it
needs 8 e- It will do almost anything to
get more e- or give away extras e-
electrons
orbitals
• Each orbital occupies only a certain amount of
electrons, these electrons are constantly in
motion.
•
1st orbital = 2 electrons
•
2nd orbital = 8 electrons
•
3rd orbital = 18 electrons
•
4th orbital = 32 electrons
• •An atom is most stable when the energy level
farthest from the nucleus is filled with the
maximum number of electrons it can hold.
The Law of conservation of mass
Matter cannot be created or destroyed
it is still there - it just changes
**So both sides must be equal**
ENERGY AND CHEMICAL REACTIONS
Living Things undergo many thousand of
Chemical Reactions as part of their life process.
REACTANTS
PRODUCTS
CO2 + H20  H2CO
Carbon Dioxide and Water  Carbonic Acid.
Balancing Equations
• 1. Balance metals
• 2. Balance polyatomic ions that stay
together; i.e. SO4 , NO3
• 3. Balance non-metals
• 4. Balance Hydrogen
• 5. Balance Oxygen
Balancing Equations
1
1
2
__Ca(OH)
2 + __HNO
3  __
3)2
2 H2O + __Ca(NO
•
•
•
•
Balance Ca
The NO3 stays together, balance it next
Balance hydrogen
Balance Oxygen
The mass of the reactants and the products must be equal
Balance the equation below, the boxes should get the
coefficients.
2
C
2
Which element does not have the same number
of atoms on both sides? Oxygen. It has 2 on
the reactant side and 3 on the product side. If
we put a coefficient of 2 in front of PbO, we will
now have 4 O and 2 Pb on the right. By placing
a coefficient of 2 in front of the reactant, we
have 2 Pb and 2 x 2 O. That means it is
balanced
2
K + 2HOH
H2O  2 KOH + H2
19 What is the coefficient for H2O when
the above equation is balanced?
• A 1 To balance this equation, make water
HOH, then you will see that you need
• B2
2 H and get 2 OH groups.
• C3
That means the KOH gets a coefficient
• D 4 of 2, the K gets a coefficient of 2 and
The water must also get a coefficient
of 2.
Try this one!
According to the graph,
about how much
hemoglobin would be
saturated at an O2
pressure of 7.3 kPa?
A 32%
B 67%
C 89%
D 92%
Dmitri Mendeleev
Organized all the elements
Columns
Rows
* Elements in the same column are
called a group.
*They usually have the same number
of valance electrons.
* They have similar properties.
*The left columns (metals) give electrons
*The right columns (non-metals) take
electrons
Column titles indicate their Group number
Group I (1A) – has 1 valance electron, it is very
reactive
Group II (2A) – has 2 valance electrons, not as
reactive
And so on…
Group 17 (7A) - elements have 7
electrons in their valance shell, (they
want 1 more electron to make 8)
*very reactive
Group 18 - NOBLE GASES are
INERT GASES (not reactive)
Full valance shell, (8 electrons)
* stable
Rows is considered to be a different period
(Like school periods).
All of the elements in a period have the same number of atomic orbital (shells)
Every element in the top row has one orbital.
elements in the second row have two orbitals….etc.
ROWS
Elements
Chemical elements are the fundamental
materials of which all matter is
composed
Helium atom
• An element is a substance that cannot be
broken down into simpler chemical
substances.
• Atoms of the same element that have
different numbers of neutron are called
isotopes.
Hydrogen
Atomic Mass = 1
Atomic Number = 1
Deuterium
Atomic Mass = 2
Atomic Number = 1
Periodic Table
What do the numbers mean?
Atomic Number.
11
Na
22.990
sodium
The number of protons in a
single atom, of this element.
It's also the # of electrons.
The symbol for this element.
Atomic mass The number of
protons + neutrons, or the
mass of the nucleus of an
atom.
Name of the element.
Atomic Symbol
usually the first letter (s) of the elements name
Carbon = C
Oxygen = O
***Sometimes we use the Latin name
Sodium= Natrium = Na
Lead= Plombum = Pl
Atomic Mass
Is the atomic weight and the number of
protons and neutrons in the atom
Protons + Neutrons = Atomic Mass
The Mole and Molecular Weights
One mole equals 6.02 x 1023 (also known as
Avogadro's number).
One mole of hydrogen atoms (6.02 x 1023 H
atoms) weighs 1 g. (And so forth….)
To Calculate
the Mass
11
Look for the
Mass of the
element on
the Periodic
chart
Na
22.990
sodium
The Law of Conservation of Mass
When numbers for mass are involved, change the yield
arrow to an equal sign and work like a simple math
problem.
C + O2 
CO2
carbon
12 mass units
oxygen
Carbon dioxide
32 mass units
44 mass units
12 mass units + ? = 44 mass units
? = 44 – 12
? = 32 mass units
According to the law of conservation of mass,
how much zinc was present in the zinc
carbonate?
Since matter can not be created or destroyed in
A 40 g
B 88 g
C 104 g
D 256 g
chemical reactions, the mass on both sides of the arrow
must be equal. So 64g + 192g = 256g and 152 g + Zinc = 256g
There must be 104g of Zinc. Answer C.
Periodic Table
4 Basic Types of Elements
• Metals: found on the left and center
• Non-metals: found on the right side .
• Metalloids: found along the stair-step
line
*Synthetic: made in the laboratory, not
found in nature
Where are the nonmetals?
To the Right of the stair step line, and Hydrogen!
Noble
gases
Chemical Reactivity
Nonmetals get
more reactive
up & to the right
Metals get more
reactive
left & down
Most reactive metal is?
Fr
Most reactive nonmetal is?
F
atomic radius of an element is a measure of the size
of its .
Problem:
Which of the following groups
contains members with similar
chemical reactivity?
A Li, Be, C
B Be, Mg, Sr
C Sc, Y, Zr
D C, N, O
Answer:
Lets look at the Table provided.
To have similar
chemical
properties, they
must be in the
same Group.
*Groups are columns, so the
answer would be
B
electromagnetic force.
• Atoms are bonded by an electromagnetic force.
• The electrons are negative the protons are positive
• They act like magnets and stick together
Chemical Reactions
• The forming or breaking of bonds that cause
substances to combine in different ways to make
other substances are called chemical reactions.
2H2 + O2
2H2O
All of the chemical reactions that take place within an organism are known as
that organism’s metabolism
Covalent Bond –
Ex: Hydrogen and Oxygen bond to form water
Non-metals share their electrons with other non-metals
*weak
Covalent Bonds:
Dogs of equal strength
Ions & Ionic Bonds
• ion- atoms that gained or lost electrons when bonding
•
Cations -positively-charged ions
•
Anions -negatively-charged
• ionic bond - force between two ions of opposite charge
• Ex: Sodium and Chlorine bond to form table salt
---These bond together----
IONIC BOND
Metals donate e- and form ionic bonds with
non-metals
*strong bonds
Positive & negative magnetic charges hold them together
salt
Ionic Bonds: One big greedy thief dog
Metallic bonds
• These bonds are best imagined as a room
full of puppies who have plenty of bones to
go around and are not possessive of any one
particular bone. This allows the electrons to
move through the substance with little
restriction.
Metallic Bonds: Mellow dogs with plenty of
bones to go around
Diatomic molecule
• Consists of 2 atoms of the element
• Example- oxygen – O2
Polyatomic molecule
• Many molecules
• Small groups of
covalently bonded atoms
can gain or lose electrons
to form polyatomic
molecules
Hydrocabons
Nuclear Changes: Fission and Fusion
• Fusion - the nucleus of
one atom joins the nucleus
of another.
• Releases extreme energy
• the sun and stars.
• Fission -the nucleus of an atom
breaks apart
• Release extreme energy
• atomic energy plants
• bombs.