g rade 8 staar s cience r eview written by chris jackson, ed.d. © hedgehog learning

GRADE 8 STAAR SCIENCE REVIEW

Written by Chris Jackson, Ed.D.

www.hedgehoglearning.com

© Hedgehog Learning

http://www.hedgehoglearning.com/


Grade 8 STAAR Science Review


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

STAAR Review DAY 1MATTER AND ENERGYTEKS 8.5A (R), 8.5B (R), 7.5C (S), 7.6A (S), 7.6B (S)



Structure of AtomsProtons, Neutrons, and Electrons

Nucleus of the Atom- Contains Protons and NeutronsElectron Cloud of the Atom- Contains Electrons


Protons, Neutrons, and Electrons

Protons Neutrons Electrons

Mass of Particle(1, 0)

Charge of Particle(-1, 0, +1)

Location of Particle

Take a minute to fill in the table below on a piece of paper…


Protons, Neutrons, and Electrons

Protons Neutrons Electrons

Mass of Particle(1, 0)

1 1 0

Charge of Particle(-1, 0, +1)

+1 0 -1

Location of Particle

Nucleus Nucleus Orbitals or Electron

Cloud

Is this what you came up with?


Makeup of an Element

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.


Memory Tricks


Memory Tricks

tomic #

rotons(personality of atom)

lectrons

SAME#

ass (protons + neutrons)

tomic #

umber of ueutrons

rotons(personality of atom)

o charge ueutrons

lectrons


Gaining (or Losing) a Charge!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.


Gaining (or Losing) a Charge!

12 P 8 P

Mg O

= VALENCE ELECTRON


Gaining (or Losing) a Charge!

12 P 8 P

= VALENCE ELECTRON

Mg O

Lose 2 Electrons

+2 Charge

Gain 2 Electrons-2 Charge


Reactivity

• 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.


Chemical and Physical Changes in the Digestive System

Identify examples of physical and chemical changes that occur at each of these points.A

BC


Chemical and Physical Changes in the Digestive System

A – Chewing and swallowing (physical) and saliva (chemical)B – Stomach acids breakdown proteins and fats (chemical)C – Absorption of water (physical) and breakdown of proteins, fats, and carbohydrates (chemical). A

BC


Energy and Food Webs

On a piece of paper, diagram the flow of energy through these organisms.


Energy and Food Webs

SUN


Organic Compounds

Organic Compounds are compounds containing carbon.

Organic compounds are the building blocks of life, including substances like fats, sugars, and protein.

Fossil fuels are also organic compounds.

Can you identify any other carbon-containing compounds?

CARBON

Hydrogen

Oxygen

SulfurNitrogen

Phosphorus


Memory Tricks

NCHOPS


Memory Tricks

NCHOPS

itrogen

arbon- must be present in an organic molecule!

ydrogen

xygen

hosphorus

ulfur

STAAR Review DAY 2MATTER AND ENERGYTEKS 8.5C (R), 8.5D (R), 6.5C (S), 6.6A (S), 6.6B (S)



Periodic TableP

ER

IOD

S

GROUPS


Memory Tricks


Periodic Table

METALSAlkali and Alkaline MetalsTransition Metals

• Conducts heat• Conducts electricity• Solid• Lustrous• Malleable


Periodic Table

METALLOIDS• Semiconductors of electricity

• Properties of metals and nonmetals


Periodic Table

NONMETALS

• Gas or Liquid• Poor conductors

of electricity and heat

• Reactive with metals

• Noble gases (green column) are unreactive.


Chemical ReactionsElements and Compounds

2AB + C2 2CB + 2A

Reactants

Products

Coefficient Subscript Compound Element

STAAR Review DAY 3MATTER AND ENERGYTEKS 8.5E (R), 8.5F (S)



Chemical Changes

a change when a new substance is formed from the reaction between two

or more different substances

CHEMICAL CHANGE


Physical Changes

a change in the temperature, state of

matter, shape, density, or any other observable

characteristic of a substance

PHYSICAL CHANGE


Memory TricksFill in the missing information

ABCD

SSSSS



A new substance

Bubbles or odor (gas formation)

Color change (unexpected)

Different temperature

Same substance

Shape

Size

State of matter (phase change)

Solution (salt water)


Law of Conservation of MassMass 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?


Law of Conservation of MassMass of Reactants = Mass of Products

Before

After

How does the mass of the egg change before and after cooking?A: THE MASS REMAINS THE SAMEDo the physical and chemical changes affect the mass?A: THE CHANGES DO NOT AFFECT THE MASS OF THE EGG


Memory Tricks


Balancing of Chemical EquationsLaw of Conservation of Mass in Chemical Reactions

H2 + O2 H2O

On a piece of paper, balance this reaction between hydrogen and

oxygen gas.


Balancing of Chemical EquationsLaw of Conservation of Mass in Chemical Reactions

2H2 + O2 2H2O

4 atoms of Hydrogen on both sides

2 atoms of Oxygen on both sides

Was this your answer?

STAAR Review DAY 4FORCE, MOTION, AND ENERGYTEKS 8.6A (R), 8.6B (S), 6.8C (S), 6.7D (S)



ForcesConsider the forces acting on these books.

Are the books moving?

Are the forces balanced or unbalanced?

Gravity pulling downward

Table pushing upward

Air pressu

re

Air pressu

re


ForcesConsider the forces acting on these books.

Are the books moving?A: NO

Are the forces balanced or unbalanced?A: BALANCED

Gravity pulling downward

Table pushing upward

Air pressu

re

Air pressu

re


ForcesBalanced 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

Identify if these items are examples of BALANCED or UNBALANCED forces.

Constant speed


Balanced or UnbalancedWhat is the net force acting on these objects? Will these objects change speed?

15 N

25 N

3 N 1 N

2 N

2 N


Balanced or UnbalancedWhat is the net force acting on these objects? Will these objects change speed?

15 N

25 N

3 N 1 N

2 N

2 N

NET: 10 N Down

NET: 2 N Forward


Speed, Velocity, and Acceleration

• 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?


Speed, Velocity, and Acceleration

• 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

Average Speed: 375 miles/hourVelocity: 375 miles/hour to the northeastPositive acceleration occurs at takeoff; Negative acceleration occurs at landing

STAAR Review DAY 5FORCE, MOTION, AND ENERGYTEKS 8.6C (R), 7.7A (S), 6.8A (S), 6.9C (S)



Newton’s 3 Laws of Motion

#3 – every action has an equal and opposite reaction

#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


Which Law of Motion?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.


Which Law of Motion?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.

- 3rd Law of Motion• An airbag inflates to help cushion to rapid deceleration of

the people inside the car during an accident.- 1st Law of Motion

• A powerful rocket engine producing more force is used on a more massive rocket to produce the same acceleration.

- 2nd Law of Motion


Energy

Potential EnergyThe energy that results due to an object’s position

Kinetic EnergyThe energy derived from an object’s motion

When is kinetic energy converted to potential energy during a roller coaster ride?

Highest Potential Energy

Highest Kinetic Energy


This is so much WORK!

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?

Would the amount of work change if she used a ramp to help her?

2 m

5 kg


This is so much WORK!

Work – the energy needed to move an object over a certain

distanceForce = mass x accelerationForce = 5 kg x 9.8 m/s2 (gravity)

Force = 49 Newtons

Work = force x distanceWork = 49 N x 2 mWork = 98 Joules

A ramp would reduce the required force, but the distance would increase. The amount of work would not change.

2 m

5 kg


Energy Conversions

Name the energy conversions in each of the pictures to the right using the following terms:

Solar EnergyMechanical EnergySound EnergyChemical EnergyElectrical EnergyLight Energy


Energy Conversions

Name the energy conversions in each of the pictures to the right using the following terms:

Solar EnergyMechanical EnergySound EnergyChemical EnergyElectrical EnergyLight Energy

solar to electrical

electrical to light

wind to electrical

electrical to sound

chemical to electrical

STAAR Review DAY 6EARTH AND SPACETEKS 8.7A (R), 8.7B (R), 8.7C (S), 6.11B (S)


Rotation of Earth

ROTATION OF THE EARTH


The Earth rotates once every 24 hours or 1 day.

The rotation of the Earth causes day and night since the side facing the Sun is always moving.

The rotation of the Earth does not cause seasonal changes.

sunlightDAYNIGHT

Revolution of Earth

REVOLUTION OF THE EARTH


The Earth revolves around the Sun every 365 days or 1 year.

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.

SUMMER

SUMMER

WINTER

WINTER


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?


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?A: New Moon

What phase of the Moon will occur about one week after the first quarter?A: Full Moon


Memory TricksFill in the missing parts of the memory tricks on your own paper

Nina’sCousinQuit GamblingForever

RLNL

F


Memory Tricks

Nina’s- New Moon

Cousin- crescent

Quit- quarter

Gambling- gibbous

Forever- full moon

RLNL

F

eft IghteavingIl’ wane

ew moono moonear the sun

ull moonull of lightar from sun

ight lighteturning waxing


Please understand the GRAVITY of the situation…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.


Tidal Forces – Moon and Sun

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)


Memory Tricks

Fill in the missing parts of the memory tricks on your own paper


Memory Tricks

Fill in the missing parts of the memory tricks on your own paper

pring tidetraight across

eap tideInety degrees

ow tide

STAAR Review DAY 7EARTH AND SPACETEKS 8.8A (R), 8.8B (S), 8.8C (S), 8.8D (S)



We are just a speck…

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

If we were traveling at the speed of light, it would take us _________ to reach ________.


Solar SystemOur own personal star

Our solar system is extremely tiny compared to the Milky Way Galaxy.


StarsThe 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.

http://en.wikipedia.org/wiki/File:Pleiades_large.jpg


Life Cycles of Stars

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?

Hotter Cooler

Bri

ghte

r


Galaxies

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

http://en.wikipedia.org/wiki/File:Hubble2005-01-barred-spiral-galaxy-NGC1300.jpg

STAAR Review DAY 8EARTH AND SPACE TEKS 8.9B (R), 8.9C (R), 8.9A (S), 8.10A (S), 8.10B (S), 8.10C (S), 7.8C (S)



Plate TectonicsWhat do the orange dots represent?


Crustal Features

Which of these two landscapes is hundreds of miles away from a crustal boundary?

Give a reason to support you answer.


Crustal Features

Near a plate boundary

Far away from a plate boundary


Memory TricksFill in the missing parts of the memory tricks

CD

T


Memory TricksFill in the missing parts of the memory tricks

CD

TonvergentolliderashCome together

ivergentivide

ransform l i d e


Plate Tectonics

1 23

At which number on the map are the following crustal features occurring?

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.


Plate Tectonics

1 23

At which number on the map are the following crustal features occurring?

A.2 - Tall mountain range formed from one plate moving into another plate.

B.1 - A mid-ocean ridge where two plates are separating.

C.3 - Earthquakes where two plates are moving past each other.


Erosion and WeatheringConstant 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?


Erosion and WeatheringConstant reshaping of our planet

What features can you identify in this satellite picture?

What are the brown areas?A: Sediment

Where does this come from?A: Erosion from landscapeWhere is it going?A: Deposited at river deltas



Weathering __________it!

Erosion ______________it!

Deposition ___________it!



Weathering breaks it!

Erosion takes it!

Deposition drops it!

Weather Symbols

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?

What is responsible for all moving currents, both in the atmosphere and in the ocean?

H L© Hedgehog Learning

Weather Symbols

In which direction to high pressure systems rotate in Texas?A: Clockwise

Where is the world would they rotate the other direction?A: Southern Hemisphere

What is responsible for all moving currents, both in the atmosphere and in the ocean?A: Energy from the Sun

H L© Hedgehog Learning


Hurricanes

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?


Memory Tricks

Fill in the missing information

H L


Memory Tricks


H L

Looks like icicles– cold frontLooks like teeth- violent storms that PUSH through

Looks like suns- warm frontLook like gums- gentle storms that glide through

igh pressureappy weather

s ine

ow pressureousy weather

c ouds


Hurricanes

Hurricanes occur in the Atlantic ocean during the summer and fall. Why do they occur during this time and not during the winter?A: Oceans are warmer; provide energy

Where does the energy for hurricanes come from?A: Energy from the Sun

In which direction to hurricanes rotate in the Northern Hemisphere? Counter-clockwise. Southern Hemisphere? Clockwise.

STAAR Review DAY 9ORGANISMS AND ENVIRONMENTSTEKS 8.11A (R), 8.11B (R), 7.10B (S), 7.10C (S), 7.11C (S), 8.11D (S)


Food Webs and Energy

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?


Food Webs and Energy

SUN – Source of Energy

PRODUCERS – Plants

CONSUMERS – Rabbit, Grasshopper, Snake, Mouse, Eagle

DECOMPOSER – Ant

If the rabbit population decreased, the snake population would as well. © Hedgehog Learning


Parasites

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?


Memory Tricks



Memory Tricks


Parasitism- one benefits, the other is harmed

Commensalism- one benefits, the other is not harmed

Mutualism- both benefit

Ecosystems

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?



Ecosystem

In this ocean ecosystem, how are organisms are competing for:

• Sunlight• Living space• Food• Oxygen


Natural SelectionHow does natural selection explain why giraffe’s have long necks?Why is biodiversity important to natural selection?


Natural SelectionHow does natural selection explain why giraffe’s have long necks?Why is biodiversity important to natural selection?

Natural selection would suggest that only the giraffes with long necks would be able to reach the leaves on the trees.

Biodiversity indicates there are many gene traits among all the giraffes for natural selection to “choose” from.

STAAR Review DAY 10ORGANISMS AND ENVIRONMENTSTEKS 8.11C (R), 7.11A (S), 7.12B (S), 7.12D (S), 7.12F (S), 7.14B (S), 7.14C (S), 6.12D (S)



Traits and Environmental Changes

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?


Traits and Environmental ChangesGenetic 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.


Dichotomous Keys

Dichotomous keys help us to identify organisms based on their physical characteristics.

What is the dichotomous key in the picture used to identify?


Body Systems


Reproduction

Sexual ReproductionRequires male and femaleFewer offspringGreater genetic variation

Asexual ReproductionRequires only one parentMany offspringLess genetic variation

What are the advantages of sexual reproduction in fighting off certain illnesses over multiple generations?

Some plants can reproduce asexually.

Animals reproduce sexually and produce fewer offspring.


Parts of a Cell

Parts of a Cell

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?


Parts of a Cell

Parts of a Cell

Looking at the diagram on the right:

1. Where is the genetic material contained? Nucleus

2. Is this cell prokaryotic or eukaryotic? Eukaryotic

3. Is this cell autotrophic or heterotrophic? Autotrophic

4. Would this cell be found in the animal kingdom? No


Human Interaction with the OceansBuilding 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?

Best wishes for success on the Grade 8 Science STAAR!

Written by Chris Jackson, Ed.D.

www.hedgehoglearning.com




g rade 8 staar s cience r eview written by chris jackson, ed.d. © hedgehog learning

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