STAAR® State of Texas Assessments of Academic Readiness GRADE 8 Science Administered May 2021 RELEASED Copyright © 2021, Texas Education Agency. All rights reserved. Reproduction of all or portions of this work is prohibited without express written permission from the Texas Education Agency. STAAR GRADE 8 SCIENCE STAAR State of Texas REFERENCE MATERIALS Assessments of Academic Readiness FORMULAS mass Density = volume total distance Average speed = total time Net force = (mass)(acceleration) 1 18 1A 8A 1 Atomic number 14 2 1 H He Symbol 1.008 2 13 14 15 16 17 4.0026 Si Hydrogen 2A 3A 4A 5A 6A 7A Atomic mass 28.085 Helium 3 4 5 6 7 8 9 10 Silicon Name 2 Li Be B C N O F Ne 6.94 9.0122 10.81 12.011 14.007 15.999 18.998 20.180 Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon 11 12 13 14 15 16 17 18 3 Na Mg Al Si P S Cl Ar 3 4 5 6 7 22.990 24.305 8 9 10 11 12 26.982 28.085 30.974 32.06 35.45 39.948 Sodium Magnesium 3B 4B 5B 6B 7B 8B 1B 2B Aluminum Silicon Phosphorus Sulfur Chlorine Argon 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.098 40.078 44.956 47.867 50.942 51.996 54.938 55.845 58.933 58.693 63.546 65.38 69.723 72.630 74.922 78.971 79.904 83.798 Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 85.468 87.62 88.906 91.224 92.906 95.95 101.07 102.91 106.42 107.87 112.41 114.82 118.71 121.76 127.60 126.90 131.29 Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon 55 56 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 6 Cs Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 132.91 137.33 174.97 178.49 180.95 183.84 186.21 190.23 192.22 195.08 196.97 200.59 204.38 207.2 208.98 Cesium Barium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury Thallium Lead Bismuth Polonium Astatine Radon 87 88 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 7 Fr Ra Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og Francium Radium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Atomic masses are not listed for elements with no stable or common isotopes. 57 58 59 60 61 62 63 64 65 66 67 68 69 70 Lanthanide Series La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb 138.91 140.12 140.91 144.24 150.36 151.96 157.25 158.93 162.50 164.93 167.26 168.93 173.05 Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium 89 90 91 92 93 94 95 96 97 98 99 100 101 102 Actinide Series Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No 232.04 231.04 238.03 Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Updated 2017 Source: International Union of Pure and Applied Chemistry SCIENCE Science Page 5 DIRECTIONS Read each question carefully. For a multiple-choice question, determine the best answer to the question from the four answer choices provided. For a griddable question, determine the best answer to the question. Then fill in the answer on your answer document. 1 Immediately after a forest fire, the primary consumers in the area will compete most for which biotic factor? A Food B Space C Oxygen D Sunlight 2 A steel ball is at one end of a box that is moving forward as shown. The box suddenly stops. According to Newton’s first law, what happens to the steel ball just after the box stops? F Because of friction, the ball continues rolling forward at the same speed. G Because of friction, the ball rolls forward at an increased speed. H Because of inertia, the ball continues rolling forward at the same speed. J Because of inertia, the ball rolls forward at an increased speed. Science Page 6 3 Students mixed two liquids in a beaker and listed their observations. Observations Liquid 1 was colorless. Liquid 2 was colorless. The mixture of liquids 1 and 2 formed a colorless solution. Small, solid particles formed and fell to the bottom of the beaker. Based on these observations, which statement contains the best evidence that a chemical reaction occurred? A There is a change in shape. B There is a change in volume. C The two liquids mix into a solution. D The two liquids form a new substance. Science Page 7 4 The diagram shows Earth in its orbit around the sun when very little light is visible at Earth’s South Pole. Which statement is true when Earth is in the position shown? F It is August in the Northern Hemisphere. It is April in the Southern Hemisphere. G It is summer in the Northern Hemisphere. It is winter in the Southern Hemisphere. H The number of hours of daylight is greater in the Southern Hemisphere than in the Northern Hemisphere. J Spring begins earlier in the year in the Southern Hemisphere than it does in the Northern Hemisphere. Science Page 8 5 Tiny organisms called Daphnia live in lakes and ponds where they consume algae. A lake with a stable population of algae and Daphnia was contaminated by pollution, resulting in the death of many algae. Which graph shows the most likely trend in the Daphnia population in the lake shortly before and after the pollution event? Daphnia in Lake Daphnia in Lake Pollution Pollution event event A C Population Population Population Daphnia Daphnia Time Time Daphnia in Lake Daphnia in Lake Pollution Pollution event event B D Population Population Population Daphnia Daphnia Time Time 6 A student pushes a 51.5 kilogram bookshelf across a smooth floor with a net force of 67 N. What is the approximate acceleration of the bookshelf? F 1.3 m/s2 G 3,450.5 m/s2 H 15.5 m/s2 J 0.77 m/s2 Science Page 9 7 A topographic map provides details about Emory Peak in Big Bend National Park. A radio tower on Emory Peak is indicated. Emory Peak Topographic Map 2,255 Emory Peak 2,385 N EW 2,245 S KEY Contour interval: 10 m Radio tower Based on the topographic map, if a park ranger hiked due west from the radio tower, the ranger’s path would — A cross a canyon with a river running through it B cross another peak in the park C be flat and then go up a steep slope D go down a steep slope and then become flatter 8 Which pair of elements are nonmetals and gases at room temperature and normal atmospheric pressure? F Fluorine, F, and chlorine, Cl G Boron, B, and aluminum, Al H Hydrogen, H, and cesium, Cs J Cobalt, Co, and nickel, Ni Science Page 10 9 A farmer digs a small pond in a pasture. The farmer adds young individuals from two species of algae-eating fish to the pond and plants some reeds around the edges of the pond. The farmer wants the pond to be a sustainable ecosystem. Which of the following would be most helpful in increasing the pond ecosystem’s sustainability? A Decreasing the number of plant species around the edges of the pond B Introducing older fish of the same species into the population of algae-eating fish C Having a greater diversity of living organisms in the pond D Adding gravel between the water and where the reeds are planted 10 A student investigates the motion of a toy vehicle. The student graphs 40 seconds of data from the investigation. Motion of a Toy Vehicle 15 10 5 Distance (meters) 0 10 20 30 40 50 Time (seconds) Which statement best describes the motion of the toy vehicle during the first 30 seconds of the investigation? F The vehicle was traveling at a constant speed. G The vehicle was accelerating at a constant rate. H The speed of the vehicle was increasing. J The acceleration of the vehicle was increasing. Science Page 11 11 How many neutrons are in the nucleus of a potassium atom with a mass number of 39? Record your answer and fill in the bubbles on your answer document. Be sure to use the correct place value. Science Page 12 12 Major surface currents of the ocean are shown in the diagram. Ocean currents affect weather patterns by — F regulating when tides occur in coastal areas G trapping heat at the equator to regulate the global climate H distributing heat from the uneven absorption of solar energy J increasing the rate of evaporation to transport water to areas experiencing droughts Science Page 13 13 Students view two different cells under a microscope.