Written by Chris Jackson, Ed.D. GRADE 8 STAAR SCIENCE REVIEW Written by Chris Jackson, Ed.D. www.hedgehoglearning.com © Hedgehog Learning

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 © Hedgehog Learning

STAAR Review DAY 1 MATTER AND ENERGY TEKS 8.5A (R), 8.5B (R), 7.5C (S), 7.6A (S), 7.6B (S) © Hedgehog Learning

Structure of Atoms Nucleus of the Atom - Contains Protons and Neutrons Protons, Neutrons, and Electrons Nucleus of the Atom - Contains Protons and Neutrons Electron Cloud of the Atom - Contains Electrons © Hedgehog Learning

Protons, Neutrons, and Electrons Take a minute to fill in the table below on a piece of paper… Protons Neutrons Electrons Mass of Particle (1, 0) Charge of Particle (-1, 0, +1) Location of Particle © Hedgehog Learning

Protons, Neutrons, and Electrons Is this what you came up with? Protons Neutrons Electrons Mass of Particle (1, 0) 1 Charge of Particle (-1, 0, +1) +1 -1 Location of Particle Nucleus Orbitals or Electron Cloud © Hedgehog Learning

Makeup of an Element © Hedgehog Learning 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.

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. © Hedgehog Learning

Gaining (or Losing) a Charge! = VALENCE ELECTRON 12 P 8 P Mg O © Hedgehog Learning

Gaining (or Losing) a Charge! = VALENCE ELECTRON Lose 2 Electrons +2 Charge Gain 2 Electrons -2 Charge 12 P 8 P Mg O © Hedgehog Learning

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. © Hedgehog Learning

Chemical and Physical Changes in the Digestive System Identify examples of physical and chemical changes that occur at each of these points. A B C © Hedgehog Learning

Energy and Food Webs On a piece of paper, diagram the flow of energy through these organisms. © Hedgehog Learning

Organic Compounds CARBON © Hedgehog Learning 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? Hydrogen Oxygen Phosphorus CARBON Nitrogen Sulfur

STAAR Review DAY 2 MATTER AND ENERGY TEKS 8.5C (R), 8.5D (R), 6.5C (S), 6.6A (S), 6.6B (S) © Hedgehog Learning

Periodic Table GROUPS PERIODS © Hedgehog Learning

Periodic Table METALS Conducts heat Conducts electricity Solid Alkali and Alkaline Metals Transition Metals Conducts heat Conducts electricity Solid Lustrous Malleable © Hedgehog Learning

Periodic Table METALLOIDS Semiconductors of electricity Properties of metals and nonmetals © Hedgehog Learning

Periodic Table NONMETALS Gas or Liquid Poor conductors of electricity and heat Reactive with metals Noble gases (green column) are unreactive. © Hedgehog Learning

Chemical Reactions Reactants Products 2AB + C2  2CB + 2A Elements and Compounds Reactants Products 2AB + C2  2CB + 2A Coefficient Subscript Compound Element © Hedgehog Learning

STAAR Review DAY 3 MATTER AND ENERGY TEKS 8.5E (R), 8.5F (S) © Hedgehog Learning

Chemical Changes CHEMICAL CHANGE a change when a new substance is formed from the reaction between two or more different substances © Hedgehog Learning

Physical Changes PHYSICAL CHANGE a change in the temperature, state of matter, shape, density, or any other observable characteristic of a substance © Hedgehog Learning

Law of Conservation of Mass 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? © Hedgehog Learning

Balancing of Chemical Equations Law of Conservation of Mass in Chemical Reactions H2 + O2  H2O On a piece of paper, balance this reaction between hydrogen and oxygen gas. © Hedgehog Learning

Balancing of Chemical Equations 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 © Hedgehog Learning

STAAR Review DAY 4 FORCE, MOTION, AND ENERGY TEKS 8.6A (R), 8.6B (S), 6.8C (S), 6.7D (S) © Hedgehog Learning

Forces Consider the forces acting on these books. © Hedgehog Learning 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 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 Identify if these items are examples of BALANCED or UNBALANCED forces. Constant speed © Hedgehog Learning

Balanced or Unbalanced What is the net force acting on these objects? Will these objects change speed? 2 N 15 N 3 N 1 N 25 N 2 N © Hedgehog Learning

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? © Hedgehog Learning

STAAR Review DAY 5 FORCE, MOTION, AND ENERGY TEKS 8.6C (R), 7.7A (S), 6.8A (S), 6.9C (S) © Hedgehog Learning

Newton’s 3 Laws of Motion #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 © Hedgehog Learning

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. © Hedgehog Learning

Energy Highest Potential Energy Highest Kinetic Energy The energy that results due to an object’s position Kinetic Energy The 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 © Hedgehog Learning

Work – the energy needed to move an object over a certain distance This is so much WORK! Work – the energy needed to move an object over a certain distance 5 kg 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 © Hedgehog Learning

Energy Conversions © Hedgehog Learning 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

STAAR Review DAY 6 EARTH AND SPACE TEKS 8.7A (R), 8.7B (R), 8.7C (S), 6.11B (S) © Hedgehog Learning

Rotation of Earth NIGHT DAY 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. Rotation of the earth NIGHT DAY sunlight © Hedgehog Learning

Revolution of the earth Revolution of 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. Revolution of the earth SUMMER WINTER WINTER SUMMER © Hedgehog Learning

Phases of the Moon © Hedgehog Learning 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?

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. © Hedgehog Learning

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) © Hedgehog Learning

STAAR Review DAY 7 EARTH AND SPACE TEKS 8.8A (R), 8.8B (S), 8.8C (S), 8.8D (S) © Hedgehog Learning

We are just a speck… 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 © Hedgehog Learning

Solar System Our own personal star Our solar system is extremely tiny compared to the Milky Way Galaxy. © Hedgehog Learning

Stars © Hedgehog Learning 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.

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? Brighter © Hedgehog Learning Hotter Cooler

Galaxies © Hedgehog Learning 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

STAAR Review DAY 8 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) © Hedgehog Learning

Plate Tectonics What do the orange dots represent? © Hedgehog Learning

Crustal Features Which of these two landscapes is hundreds of miles away from a crustal boundary? Give a reason to support you answer. © Hedgehog Learning

Plate Tectonics At which number on the map are the following crustal features occurring? Tall mountain range formed from one plate moving into another plate. A mid-ocean ridge where two plates are separating. Earthquakes where two plates are moving past each other. 3 1 2 © Hedgehog Learning

Erosion and Weathering 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? © Hedgehog Learning

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

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? © Hedgehog Learning

STAAR Review DAY 9 ORGANISMS AND ENVIRONMENTS TEKS 8.11A (R), 8.11B (R), 7.10B (S), 7.10C (S), 7.11C (S), 8.11D (S) © Hedgehog Learning

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? © Hedgehog Learning

Parasites © Hedgehog Learning 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?

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? © Hedgehog Learning

Ecosystem © Hedgehog Learning In this ocean ecosystem, how are organisms are competing for: Sunlight Living space Food Oxygen

Natural Selection How does natural selection explain why giraffe’s have long necks? Why is biodiversity important to natural selection? © Hedgehog Learning

STAAR Review DAY 10 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) © Hedgehog Learning

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? © Hedgehog Learning

Traits and Environmental Changes 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. © Hedgehog Learning

Dichotomous Keys © Hedgehog Learning 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 © Hedgehog Learning

Reproduction Sexual Reproduction Requires male and female © Hedgehog Learning Sexual Reproduction Requires male and female Fewer offspring Greater genetic variation 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? 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: Where is the genetic material contained? Is this cell prokaryotic or eukaryotic? Is this cell autotrophic or heterotrophic? Would this cell be found in the animal kingdom? Parts of a Cell © Hedgehog Learning

Human Interaction with the Oceans 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? © Hedgehog Learning

Best wishes for success on the Grade 8 Science STAAR! Written by Chris Jackson, Ed.D. www.hedgehoglearning.com © Hedgehog Learning