Class TAKS Review
Objective 4
Matter and Change
Matter
• Anything
that has
mass and
takes up
space.
• Energy is
NOT matter
Matter is divided into 3
types:
• Elements
• Compounds
• Mixtures
The 3 types can be further
separated in two categories:
• Pure Substances
• Elements are the
simplest pure
substances
• Mixtures are not
pure substances
Compounds
which
wewhen
will deal
are and
formed
two
or more
with elements
them in a
share electrons or
few
minutes.
become ions that
attract other
elements.
Atoms are. . .
• The smallest part of a
single element.
• The basis of all matter.
• Made of mostly empty
space.
• Have a positive core or
nucleus.
• Have electrons in orbit in
clouds.
4 Basic Types of Elements
• Metals: found on the left and center of the
Table of Elements
• Non-metals: found on the right side of the
Table of Elements
• Metalloids: found along the stair-step line
• Synthetic: made in the laboratory and not
yet found in nature – many of the Actinide
and Lanthanide series and very large #
elements.
Where are the metal elements?
Left of the Stair-step line!
Properties of Elements Metals
• Metals are:
–Conductors
–Lustrous
–Electron
donors
–Malleable
–Ductile
Where are the nonmetals?
To the Right of the stair step line, and Hydrogen!
Properties of Nonmetals
• Nonmetals are brittle, insulators,
electron acceptors
• Usually form negative ions (except H)
• Many are gases at room temperature
• Found to the right of the stair-step line
23 According to the periodic
table, which element most
readily accepts electrons?
• A Fluorine
•Fluorine
B Nitrogen
only needs 1
• This is a nonmetal, so it
electron
complete
itsit will
acceptstoelectrons
but
alsoofshare
in NO31shell
8, sothem
it willasaccept
it.
•from
C Arsenic
any other element
• This is a metalloid, so it only
very
very very
easily.electrons.
This
sometimes
accepts
periodic
property increases
• D Aluminum
as
youismove
upsoand
left in
• This
a metal
it donates
theelectrons.
table, except for the
Noble Gases.
The BOHR Model of an Atom
• This is the first model
to have a nucleus with
protons and neutrons.
• The electrons are in
various energy levels
and circle the nucleus.
• Model most people
draw today.
Use the Table provided!
What do the numbers mean?
11
Na
22.990
sodium
This is the atomic
number. It is the number
of protons in a single
atom of this element. By
the way, its also # of
electrons.
The symbol for this element.
This is the atomic mass, it is
the number of protons +
neutrons, or the mass of the
nucleus of an atom.
This is the name of the element.
Diatomic Elements –
Nonmetals that come as molecules
• 7 Elements are di- (2) atomic (atoms)
• The easy way to remember them is
by the name
•Br I N Cl H O F
3 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
Lets look at the Table provided.
• To have similar
chemical
properties of any
kind, they must
be in the same
Group or Family.
• Groups are
columns, so the
answer would be
•B
Chemical Reactivity
• Metals increase
in reactivity left
and down.
• Nonmetals
become more
reactive up and
to the right.
• Most reactive
metal is? Fr
• Most reactive
nonmetal is?
F
Names of Compounds – Ionic
• Ionic compounds consist of cations
(positive ions) and anions (negative ions).
• A Roman numeral in parentheses,
preceded by the name of the element, is
used for elements that can form more than
one positive ion. This is usually seen with
metals.
• Fe2+ Iron (II)
Cu+ Copper (I)
Fe3+ Iron (III)
Cu2+ Copper (II)
Ionic compounds – naming cont.
• The -ide ending is added to the name of
a single element when it becomes an ion
of that element. Oxide, Nitride, Sulfide
etc.
 Some polyatomic anions have a names
ending in -ite for the lower # of oxygens
and –ate for more oxygens.
 NO2 nitrite
NO3 nitrate
Covalent Compounds –
Names are the Formulas
• These are nonmetal to nonmetal
compounds.
• The name tells you the formula.
Carbon dioxide
1 C and 2 O
CO2
Special Names of Compounds
Acids and Bases
• Bases end in the • Acids that are two
elements are named
hydroxide anion
Hydro-nonmetal –ic Acid
OHsuch as
• They are named
– HCl hydrochloric acid
with the metal
• Group -ate becomes –ic
and hydroxide.
and -ite becomes –ous.
• NaOH is sodium
• H2SO3 sulfurous acid
hydroxide
• H2SO4 sulfuric acid
15 An advertisement claims that patients can be
cured of the common cold in 48 hours by
vitamin C tablets with secret mineral
supplements. In a scientific experiment to test
these claims, which data can be considered
irrelevant?
A The amount of vitamin C in each tablet
B The severity of the patients’ cold symptoms
C The chemical formula for vitamin C
D The amount of time before symptoms
improve
What doesn’t matter to the test?
A The amount of vitamin C in each tablet
This should be a controlled variable!
B The severity of the patients’ cold symptoms
This would be very hard to control, but a large
experimental group should allow for differences
C The chemical formula for vitamin C
Compound formulas NEVER change so this is
our answer it is irrelevant!!!
D The amount of time before symptoms improve
This is what we are testing, it is most relevant.
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)
• Chemical changes are reactions that result in
new products with new properties.
Changes in Matter –
Physical, Chemical or Nuclear?
• Physical changes do • Chemical changes
not change the
are also called
substance. The state
chemical reactions.
of the matter may
• When a different
change, but it keeps its substance is
own properties.
produced than what
• Cutting a piece of
was present at the
wood does not change start, a chemical
the wood, it is simply
change has occurred.
smaller.
Nuclear Changes: Fission and
Fusion
• Fusion occurs when
• Fission occurs when the
the nucleus of one
nucleus of an atom
atom is joined by the
ejects particles and
nucleus of another.
energy when hit by a
subatomic particle such
• This is the reaction
as a neutron.
that occurs on the sun
and stars.
• This also causes a
release of extreme
• It produces extreme
energy and is the basis
energy release.
of atomic energy plants
and bombs.
Density = Mass / Volume
THIS IS FROM THE FORMULA PAGE
25 A block of maple wood with a volume of
405 cubic centimeters and a density of
If0.67
the block
in half, in
youhalf.
cut the
in half
g/cmis3 cut
is sawed
Themass
density
AND
youtwo
cut smaller
the volume
in half,
or
of the
blocks
is so
nowMass/2
—
Volume/2
A one-fourth the original density
Mass the
x 2original
(whichdensity
is really 1) so . . . .
B one-half
Volume
2 original density
C two
times the
D the same as the original density
20 A sample of an element has a volume of
78.0 mL and a density of 1.85 g/mL. What
is the mass in grams of the sample?
Record and bubble in your answer to the
nearest tenth on the answer document.
Use the formula page, D = M/V
x
1.85 g/mL =
78.0 mL
Multiply both sides by 78.0 mL and you get:
144.3 g Grid it in!
Law of Conservation of Matter
• Matter can not be created or destroyed.
• The total mass of the substances before they
are mixed is equal to the total mass as a
mixture.
Chemical Reactions
Since matter can not
Reactants  Products
be created or
destroyed, chemical
100g total = 100g total
reactions must be
balanced in terms of
mass.
The amount of mass
you start with must
be equal to the mass
of the products.
39 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.
Chemical Equations
• Whole numbers written in front of formulas are
called coefficients. For example, 4 C6H12O6
indicates that there are 4 molecules of glucose
sugar.
• To determine how many total atoms of each
element are present, multiply the coefficients
by the subscripts for each element.
• 4 C6H12O6 would contain 24 atoms of carbon
(4 x 6), 48 atoms of hydrogen (4 x 12), and 24
atoms of oxygen (4 x 6).
To balance equations:
• The number of atoms of each type of element
on the reactant side (left of the arrow) must be
equal those on the product side (right side of the
arrow).
2 H2 + O2
2 H2 O
• There are 4 hydrogen atoms on the left (2 H2)
and 4 hydrogen atoms on the right (2 H2O)
• There are 2 atoms of oxygen (O2) on the left
and 2 atoms of oxygen on the right (2 H2O).
When a subscript is missing, it is understood to
be 1.

2
2
K + 2 HHOH
O

KOH + H2
2
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.
Balance the equation below,
the boxes should get the
coefficients.
2
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!
Answer?
C
The 3 types can be further
separated in two categories:
• Mixtures
are
• Pure
Substances
not
pure
Compounds
which
are formed
substances. Each
part when
of a two
mixture keepsoritsmore
ownelements
share electrons or
properties, andbecome
can be
ions that
• Elements are the
separated out attract
by a physical
other
simplest pure
elements.
change.
substances
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!
Let’s try a few more!
6. Copper
6. Element
7. Soda
7. Solution/Mixture
8. Steel
8. Solution/Mixture
9. Rain
9. Mixture
10. Ice-cream
10. Mixture
Click Mouse button to see answers!
Properties of Mixtures:
•Each substance retains
its own properties.
•Substances can be
present in any amount.
•Substances can be
separated by simple
p h y s i c a l m e a n s.
There are two types of mixtures:
• Heterogeneous• Homogeneous- same
mixture is not the
composition throughout.
same from place to
place.
– Kool-aid, air, brass.
– Chocolate chip
cookie, gravel, soil.
Separating Mixtures – Physical
Changes
• Separation of
mixtures could be:
• Magnetic removal (if
there is Fe, Ni, Co)
• Filtration (if there are
large particles)
• Hand sorting particles
• Decanting (pouring off
the less dense liquid)
Another technique for
separating mixtures:
Evaporation:
changing from a
liquid to vapor
state– leaves
behind the other
component.
Distillation:
– Process used to
remove vapor from
liquid by heating
– Great for
separating two or
more liquids which
have different
boiling points.
So, what is a suspension or
colloid?
•o Colloids
Suspensions
have have
small
larger
particles
particles,
that are
often
not
visible
visibleinby
size.
just looking.
An example would be
o The particles can be
coffee.
filtered out.
• However, they show the
o Tyndall
It scatters
light(see
– Nothe
Effect
Tyndall
Effect.
laser light
line).
•o They
not be the
If left can
undisturbed,
separated
filtering.
particles
will by
settle
to
the bottom.
Solutions: 2
parts
–S o l v e n t - t h e m o s t
abundant substance
in the solution.
–S o l u t e - t h e l e a s t
abundant substance
in the solution.
– Homogeneous: You can not see
any particles of either part!
The three methods to
increase the rate of solution
for a solid are?
•Heat it!
•Crush it!
•Stir it!
17 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
The three methods to increase the
rate of solution for a solid are?
•
•
•
•
Heat it! C
Crush it! D slows it
Stir it! B
So this eliminates
choices B, C & D
• Which will NOT
change it?
• A
Answer choices were:
A decreasing air pressure
B stirring the water
C increasing the
temperature of the
water
D using larger crystals of
the solid
Solubility Factors –
What will dissolve?
•
•
•
•
Solubility Rules
1. All sodium, potassium, and ammonium salts are
soluble.
2. All silver, lead, and mercury salts are insoluble.
3. All carbonates, sulfides, and hydroxides are
insoluble.
4. All nitrates and sulfates are soluble except
calcium sulfate and barium sulfate.
10 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?
What are the 3 ways to
increase the rate at
which a solid
F Decreasing the
dissolves?
water temperature
Heat it!
G Stopping the stirring
Crush it!
H Lowering the air
Stir it!
pressure
ANSWER?
J Crushing the crystal
J
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?
A solubility curve shows
51 At which
temperature
do KBr and
KNO3 have
the same
solubility?
A 27°C
B 48°C
C 65°C
D 80°C
Try this one!
49 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%
Concentrated or Dilute?
• A concentrated
solution has as little
solvent as possible.
• A dilute solution has
added solvent.
• After adding more
solvent, there is still
the same mass of
solute that you started
with.
pH is a measure of the
Strength of Acids & Bases
• Acids have 0-6.99 pH
• Bases have 7.01-14 pH
• Remember because A
begins the alphabet and
zero begins numbers
• Litmus turns red in
acids and blue in bases
• Phenothalein turns pink
in a base and stays
clear in acids.
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 and have no
Solutions
are homogeneous
Nothing
is mentioned
about temperature so B is
suspended
solids.
B invalid.
a lower temperature
NaCl solutions
are neutral
so have no
effect on
C more
dissolved
salt (NaCl)
particles
pH.
D a higher concentration of OH– ions
Now its your turn!
• See if you can complete the questions
provided. Be sure to ask a science
teacher before next Friday, if there is a
question you do not know.