Transcript Grade 8 Staar review packet File

GRADE 8
STAAR
SCIENCE
REVIEW
Written by Chris Jackson, Ed.D.
www.hedgehoglearning.com
© Hedgehog Learning
All clipart and images used in this review are either
created by Hedgehog Learning, found in public
domain, or used with permission from iStockphoto,
iClipart, Microsoft, or 123RF
© Hedgehog Learning
MATTER AND ENERGY
TEKS 8.5A (R), 8.5B (R), 7.5C (S), 7.6A (S), 7.6B (S)
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Protons, Neutrons, and Electrons
Nucleus of the Atom
- Contains Protons and Neutrons
Electron Cloud of the Atom
- Contains Electrons
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Take a minute to fill in the table below on a piece of paper…
Protons
Mass of Particle
(1, 0)
Charge of Particle
(-1, 0, +1)
Location of Particle
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Neutrons
Electrons
Is this what you came up with?
Protons
Mass of Particle
(1, 0)
Charge of Particle
(-1, 0, +1)
Location of Particle
Neutrons
Electrons
1
1
0
+1
0
-1
Nucleus
Nucleus
Orbitals or
Electron Cloud
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Makeup of
an Element
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The ATOMIC NUMBER
indicates the number of
PROTONS in an ELEMENT
The ATOMIC MASS
(rounded) indicates the
number of PROTONS plus
NEUTRONS
Only Oxygen has 8 protons,
which makes it a unique
element.
To find the number of
neutrons, subtract the
atomic number from the
atomic mass:
16 – 8 = 8
Electrons are normally
equal to the number of
protons if the charge of the
atom is zero.
Element + Element = Compound
• Most elements will either gain or lose valence electrons and
become charged.
• Nonmetals (right side of periodic table) typically gain
electrons and are negatively charged.
• Metals (left side of the periodic table) typically lose electrons
and are positively charged
• Because metals and nonmetals are oppositely charged, these
individual elements will combine to form compounds.
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= VALENCE ELECTRON
12 P
8P
Mg
O
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= VALENCE ELECTRON
Lose 2 Electrons
+2 Charge
Gain 2 Electrons
-2 Charge
12 P
8P
Mg
O
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• The number of valence electrons will determine how
reactive an element will be.
• If an element has valence electrons to gain or lose, it will be
very reactive.
• If an element has all eight valence electrons, it is considered
to be non-reactive.
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Identify examples of physical and
chemical changes that occur at
each of these points.
A
B
C
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Energy and
Food Webs
On a piece of
paper, diagram
the flow of energy
through these
organisms.
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Organic
Compounds
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Organic Compounds
are compounds
containing carbon.
Organic compounds are
the building blocks of
life, including
substances like fats,
sugars, and protein.
Hydrogen
Oxygen
Phosphorus
CARBON
Fossil fuels are also
organic compounds.
Can you identify any
other carbon-containing
compounds?
Sulfur
Nitrogen
MATTER AND ENERGY
TEKS 8.5C (R), 8.5D (R), 6.5C (S), 6.6A (S), 6.6B (S)
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PERIODS
GROUPS
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METALS
Alkali and
Alkaline Metals
Transition
Metals
•
•
•
•
•
Conducts heat
Conducts electricity
Solid
Lustrous
Malleable
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METALLOIDS
• Semiconductors of
electricity
• Properties of metals
and nonmetals
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NONMETALS
• Gas or Liquid
• Poor conductors of
electricity and heat
• Reactive with
metals
• Noble gases (green
column) are
unreactive.
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Elements and Compounds
Reactants
Products
2AB + C2  2CB + 2A
Coefficient
Subscript
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Compound Element
MATTER AND ENERGY
TEKS 8.5E (R), 8.5F (S)
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CHEMICAL CHANGE
a change when a new
substance is formed from the
reaction between two or more
different substances
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PHYSICAL CHANGE
a change in the temperature,
state of matter, shape, density,
or any other observable
characteristic of a substance
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Mass of Reactants = Mass of Products
Before
After
How does the mass of the egg change before and after cooking?
Do the physical and chemical changes affect the mass?
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Law of Conservation of Mass in Chemical Reactions
H2 + O2  H2O
On a piece of paper, balance this reaction
between hydrogen and oxygen gas.
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Law of Conservation of Mass in Chemical Reactions
Was this your answer?
2H2 + O2  2H2O
4 atoms of Hydrogen on both sides
2 atoms of Oxygen on both sides
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FORCE, MOTION, AND ENERGY
TEKS 8.6A (R), 8.6B (S), 6.8C (S), 6.7D (S)
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Forces
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Gravity pulling downward
Consider the
forces acting on
these books.
Are the books
moving?
Are the forces
balanced or
unbalanced?
Air
pressure
Air
pressure
Table pushing upward
Forces
Identify if these items are examples of
BALANCED or UNBALANCED forces.
Balanced Forces occurs when multiple
forces acting on an
objects does not
cause an object to
change its speed
Unbalanced Forces occurs when multiple
forces acting on an
object causes the
object to increase or
decrease speed
Constant speed
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What is the net force acting on these objects?
Will these objects change speed?
2N
15 N
1N
3N
25 N
2N
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• Speed – the distance an object travels in a certain amount of time
• Velocity – the speed and direction of an object
• Acceleration – a change in velocity
An airplane flies from Dallas to Boston, a distance of
1500 miles, in 4 hours. Describe the flight of the
airplane in terms of average speed and velocity. When
does the airplane accelerate?
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FORCE, MOTION, AND ENERGY
TEKS 8.6C (R), 7.7A (S), 6.8A (S), 6.9C (S)
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#1 – an object will only
change speed if acted
on by an unbalanced
force - Law of Inertia
#2 – the acceleration of
an object is related to
the its mass and the
force acting on it
F=ma
#3 – every action
has an equal and
opposite reaction
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Identify which law of motion is being represented.
• A moving red billiard ball hits the side bumper on the table
and bounces backward at nearly the same speed.
• An airbag inflates to help cushion to rapid deceleration of
the people inside the car during an accident.
• A powerful rocket engine producing more force is used on a
more massive rocket to produce the same acceleration.
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Energy
Highest
Potential
Energy
Potential Energy
The energy that
results due to an
object’s position
Kinetic Energy
The energy derived
from an object’s
motion
Highest
Kinetic
Energy
When is kinetic
energy converted to
potential energy
during a roller coaster
ride?
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Work – the energy needed to move an
object over a certain distance
The woman had to pick up a box with a
mass of 5 kg and lift it a distance of 2
meters.
How much work did she do?
2m
Would the amount of work change if
she used a ramp to help her?
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5 kg
Energy
Conversions
Name the energy
conversions in each of
the pictures to the
right using the
following terms:
Solar Energy
Mechanical Energy
Sound Energy
Chemical Energy
Electrical Energy
Light Energy
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EARTH AND SPACE
TEKS 8.7A (R), 8.7B (R), 8.7C (S), 6.11B (S)
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The Earth rotates once
every 24 hours or 1 day.
ROTATION OF THE EARTH
The rotation of the Earth
causes day and night since
the side facing the Sun is
NIGHT
always moving.
The rotation of the Earth
does not cause seasonal
changes.
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DAY
sunlight
The Earth revolves around
the Sun every 365 days or
1 year.
REVOLUTION OF THE EARTH
SUMMER
WINTER
The Earth’s revolution
causes the changes in the
seasons due to the tilt of
the Earth.
The revolution of the
Earth does not cause day
or night.
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WINTER
SUMMER
Phases of
the Moon
The Moon revolves
around the Earth
about once every
month.
What phase of the
Moon will occur about
two weeks after a full
moon?
What phase of the
Moon will occur about
one week after the
first quarter?
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Mass = Gravity
Gravity is the force that holds the solar
system together.
The mass (and thus gravity) of the Sun
keeps all the planets orbiting around it.
The mass (and thus gravity) of the Earth
keeps the Moon orbiting around it.
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The Moon has
much greater affect
on the Earth’s tides
because it is closer
to the Earth.
When the Moon,
Sun, and Earth are
aligned (new and
full Moon), the tides
are the greatest
(Spring Tide)
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EARTH AND SPACE
TEKS 8.8A (R), 8.8B (S), 8.8C (S), 8.8D (S)
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If we were traveling at the speed of light, it would take
us _________ to reach ________.
1 second
Moon
8 minutes
Sun
1 hour
Saturn
4.2 years
Nearest Star (Proxima Centauri)
6,500 years
Crab Nebulae
26,000 years
Center of the Milky Way
2,500,000 years
Nearest galaxy (Andromeda)
93,000,000,000 years
Other side of the universe
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Our own personal star
Our solar system is
extremely tiny
compared to the
Milky Way Galaxy.
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Stars
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The stars we see at night
are located “nearby” in
the Milky Way galaxy.
Stars in other galaxies are
too far away for us to see
them individually.
Stars have “life cycles”
similar to plants and
animals. Average stars,
like our Sun, are born in
nebulas and die as red
giants.
Brighter
Models, like a
Hertzsprung‐Russell diagram,
show us how stars change
over time.
Based on this diagram, what
would you say about the age
of our Sun compared to other
stars on the main sequence?
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Hotter
Cooler
Galaxies
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Our galaxy, the Milky
Way galaxy, is made up
of BILLIONS of stars.
There are BILLIONS of
galaxies in the universe.
Types of galaxies
include:
• Spiral galaxies
• Barred spiral galaxies
• Elliptical galaxies
• Dwarf galaxies
• Ring galaxies
EARTH AND SPACE
TEKS 8.9B (R), 8.9C (R), 8.9A (S), 8.10A (S), 8.10B (S), 8.10C (S), 7.8C (S)
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Which of these two
landscapes is hundreds
of miles away from a
crustal boundary?
Give a reason to support
you answer.
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At which number on
the map are the
following crustal
features occurring?
3
1
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2
A. Tall mountain range
formed from one
plate moving into
another plate.
B. A mid-ocean ridge
where two plates
are separating.
C. Earthquakes where
two plates are
moving past each
other.
Constant reshaping of our planet
What features can you
identify in this satellite
picture?
What are the brown areas?
Where does this come from?
Where is it going?
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Identify these weather symbols
and describe what they mean.
In which direction to high
pressure systems rotate in Texas?
Where is the world would they
rotate the other direction?
H L
What is responsible for all moving
currents, both in the atmosphere
and in the ocean?
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Hurricanes occur in the Atlantic
ocean during the summer and
fall. Why do they occur during
this time and not during the
winter?
Where does the energy for
hurricanes come from?
In which direction to hurricanes
rotate in the Northern
Hemisphere? Southern
Hemisphere?
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ORGANISMS AND ENVIRONMENTS
TEKS 8.11A (R), 8.11B (R), 7.10B (S), 7.10C (S), 7.11C (S), 8.11D (S)
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In the food web to the left,
what role does the Sun
play?
Identify the producers,
consumers, and
decomposers.
How does the ant play a
part in the food web?
What would happen to the
snake population if the
rabbits were over-hunted?
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Parasites
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A parasite is an
organism that must get
its energy from another
organism.
Sometimes the
relationship is mutually
beneficial.
Sometimes one
organisms causes the
other harm.
Can you think of a
parasite that benefits it
host?
What about the
mosquito in the picture?
Look at the ecosystem
in the picture to the left.
Suppose a fire disturbed
this area 10 years ago.
How has ecological
succession occurred
since then.
How is competition for
resources occurring in
this ecosystem?
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Ecosystem
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In this ocean
ecosystem, how
are organisms are
competing for:
•
•
•
•
Sunlight
Living space
Food
Oxygen
How does natural selection explain why giraffe’s have long necks?
Why is biodiversity important to natural selection?
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ORGANISMS AND ENVIRONMENTS
TEKS 8.11C (R), 7.11A (S), 7.12B (S), 7.12D (S), 7.12F (S), 7.14B (S), 7.14C (S), 6.12D (S)
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Why did the environmental changes
in the early 1900’s in England cause
the “gray” peppered moth to
decline, but the “black” peppered
moth increased in population?
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Genetic trait for skin tone and skin cancer risk
People with a genetic trait for fair skin
are more likely to get skin cancer
during their lifetime.
Fairer-skin humans generally
originated further away from the
equator than darker-skin humans.
Explain how the environment
influenced early human traits for skin
tone.
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Dichotomous
Keys
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Dichotomous keys
help us to identify
organisms based
on their physical
characteristics.
What is the
dichotomous key
in the picture used
to identify?
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Reproduction
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Sexual Reproduction
Requires male and female
Fewer offspring
Greater genetic variation
Some plants can
reproduce asexually.
Asexual Reproduction
Requires only one parent
Many offspring
Less genetic variation
What are the advantages
of sexual reproduction in
fighting off certain
illnesses over multiple
generations?
Animals reproduce
sexually and produce
fewer offspring.
Looking at the diagram on the
right:
1. Where is the genetic material
contained?
2. Is this cell prokaryotic or
eukaryotic?
3. Is this cell autotrophic or
heterotrophic?
4. Would this cell be found in the
animal kingdom?
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Parts of a Cell
Building artificial reefs to replace those damaged by humans
Many coral reefs have been
damaged or destroyed by human
activity and pollution.
In an effort to restore destroyed
reefs, scientists have created
artificial reefs like the one in the
picture.
What other ways have humans
influenced the ocean habitat?
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Best wishes for success on the
Grade 8 Science STAAR!
Written by Chris Jackson, Ed.D.
www.hedgehoglearning.com
© Hedgehog Learning