Hydrochloric acid is added to a beaker containing a piece of zinc. As a result, zinc chloride is formed and hydrogen gas is released. This is an example of (1) a chemical reaction (2) a physical change (1) a chemical reaction (3) photosynthesis (4) evaporation Which setup below would require the least force to lift a 100-gram mass a distance of 10 centimeters? (1) Provides more mechanical advantage (3 supporting ropes) Which model is used by scientists to determine the properties of elements? (1) a Punnett square (3) a pedigree chart (2) the Periodic Table (4) the rock cycle (2) the Periodic Table Base your answers to the following questions on the diagram below, which shows two insulated Styrofoam cups of water connected by an aluminum bar. The thermometers show the temperature of the water in cup A and cup B at the beginning of a heat-flow experiment. Which process is most responsible for the temperature changes that will take place? (1) radiation of heat from the water in the cups to the thermometers (2) conduction of heat through the aluminum bar (3) radiation of heat from the water in the cups into the air (4) conduction of heat through the air to the water in the cups (2) conduction of heat through the aluminum bar Over the next 15 minutes, which changes would most likely occur? (1) The temperature in cup A will decrease and the temperature in cup B will increase. (2) The temperature in cup A will decrease and the temperature in cup B will decrease. (3) The temperature in cup A will increase and the temperature in cup B will increase. (4) The temperature in cup A will increase and the temperature in cup B will decrease. (1) The temperature in cup A will decrease and the temperature in cup B will increase. The diagram below shows a pencil in a glass of water. When viewed from the side, the pencil appears to be broken. What process causes this to happen? (1) absorption (3) reflection (2) evaporation (4) refraction (4) refraction A student was given samples of four different liquids, A, B, C, and D. The student poured equal amounts of two different liquid samples into several test tubes. The results are shown in test tubes 1, 2, 3, and 4. What physical property of the liquids causes them to separate into different layers when poured into the test tubes? Density When equal amounts of liquids A, B, C, and D were placed into test tube 5, the liquids separated into four layers. A diagram of test tube 5 appears below. On the blank lines next to each layer, list the final order of the liquids as they would appear in test tube 5.  D C B A Base your answers to the following questions on the diagram below and on your knowledge of science. The diagram shows a phase change represented by letter A. State the term for the phase change that occurs at A. freezing Explain why the phase change at A is a physical change There is no change into a new substance Base your answers to the following questions on the diagram below and on your knowledge of science. The diagram shows two students ready to dive into a pool. Explain why student B has more potential energy than student A. Student B is higher over the pool than student A Student A dives from the board into the water. Explain why student A's kinetic energy decreases as the student enters the water. The water slows them down and decreases their kinetic energy Base your answers to the following questions on diagram 1 and diagram 2 below and on your knowledge of science. The amount of force required to keep the same block of wood moving across the tabletop is shown in the diagrams. Circle the name of the device in the diagrams used to measure force. spring scale voltmeter thermometer graduated cylinder What change could be made in the setup in diagram 1 to increase the amount of force necessary to move the block of wood? Add more mass to the block of wood. Explain why the round pencils in diagram 2 decreases the amount of force necessary to move the block of wood. It changes sliding friction into rolling friction. The diagram below shows an experiment to test a certain property of liquids. Which property of the liquid is being tested? (1) density (2) magnetic attraction (3) conductivity (3) conductivity (4) freezing point A wet shirt is put on a clothesline to dry on a sunny day. The shirt dries because water molecules (1) gain heat energy and condense (2) gain heat energy and evaporate (3) lose heat energy and condense (4) lose heat energy and evaporate (2) gain heat energy and evaporate The diagram below shows a tall beaker with four different liquids and their densities. If a ball that has a density of 1.73 g/cm3 is placed in the beaker, where will the ball come to rest? (1) on top of liquid A (2) between liquids B and C (3) between liquids C and D (4) on the bottom of the beaker (3) between liquids C and D The four diagrams below model the results of mixing atoms of different substances. Each atom is represented by a different symbol. Which diagram correctly models a chemical change? (2) All the particles are equally distributed (in a set ratio). The diagrams below show a person moving a 50-kilogram object up a ramp. In which diagram is there the least amount of friction on the object? (4) The wheels and smooth surface create less friction. Which graph below shows an object slowing down? (1) Speed is decreasing over time. Note that this question has only three choices. As altitude increases, air pressure (1) decreases (2) increases (3) remains the same (1) decreases The table below shows the chemical symbols for some common elements. Based on the information in the table, which of the four substance below is a compound? (1) CO (2) He (3) Si (4) Fe (1) CO Element Symbol Hydrogen H Helium He Oxygen O Silicon Si Carbon C Iron Fe Base your answers to the following questions on the information below. Models are often used to explain natural phenomena. Develop a model to show the relationship between heat energy and the motion and position of particles in a sample of matter. Use a group of 20 students in an empty room to represent the particles in a sample of matter. How should the students be placed in the room to represent the arrangement of particles in a solid? Students should be close together and not moving. Base your answers to the following questions on the information below. Models are often used to explain natural phenomena. Develop a model to show the relationship between heat energy and the motion and position of particles in a sample of matter. Use a group of 20 students in an empty room to represent the particles in a sample of matter. What instruction should be given to the 20 student “particles” to show the addition of heat to the “solid sample of matter”? (Note: The solid is simply being heated; it should not melt.) They should stay in their position but start to vibrate more. Base your answers to the following questions on the information below. Models are often used to explain natural phenomena. Develop a model to show the relationship between heat energy and the motion and position of particles in a sample of matter. Use a group of 20 students in an empty room to represent the particles in a sample of matter. What instruction should be given to the 20 student “particles” to represent a liquid? They should stay close together but start moving around. The diagram below shows a boy observing a fish located at position B below the surface of the water. The boy sees the fish at position A. The apparent position of the fish is different from the actual position of the fish. What has happened to the light passing through the water to cause this difference? (1) reflection (2) absorption (3) compression (4) refraction (4) refraction The diagram below shows two dogs pulling on a rope with constant but unequal forces. In which compass direction will both dogs most likely move? (1) east (2) west (3) north (4) south (1) east The illustration below shows a student approaching the door to a building. Which two simple machines are being used to enable the student to reach the door? (1) inclined plane and pulley (2) lever and wheel-and-axle (3) pulley and lever (4) wheel-and-axle and inclined plane (4) wheel-and-axle and inclined plane Which graph correctly shows the effect of heat energy on the motion of molecules of matter? (3) The tiny particles that make up all matter are called (1) genes (2) atoms (3) minerals (4) cells (2) atoms The diagram below shows the relative wavelengths for several types of electromagnetic energy. Which type of electromagnetic energy has a shorter wavelength than ultraviolet waves? (1) visible light (2) microwaves (3) x rays (4) infrared light (3) x rays A television set changes electrical energy to sound and light energy. In this process, some energy is (1) created (2) destroyed (3) changed to matter (4) changed to heat (4) changed to heat Base your answers to the following questions on the graph below and on the data table. The graph shows the amounts of three solid solutes that will dissolve in 100 grams of water at various temperatures. Using the graphed data, describe the relationship between the temperature of the water and the amount of solute that will dissolve. As the temperature of the water increases, The amount of solute dissolved increases. The items listed below were found in a science classroom. • a heart made of plastic with many of its parts labeled • clay formed to look like Earth and other planets • a giant plastic plant cell with removable cell parts These items are all examples of (1) models (2) experiments (3) variables (4) controls (1) models Which graph best represents the relative distance between the particles of most substances in their solid, liquid, and gas states? (1) Which scientific model could be used to predict the properties of an element? (1) closed loop system (2) Punnett square (3) Periodic Table (4) water cycle chart (3) Periodic Table The diagram below shows a ball held in place by two blocks. The diameter (width) of the ball is shown between the two blocks. What is the diameter of the ball? (1) 6.0 cm (2) 8.0 cm (3) 14.0 cm (4) 17.0 cm 6.0 cm The diagram below shows a boulder rolling down a hill into a valley and then up the opposite hill. At which position does the boulder have the greatest kinetic energy? (1) A (2) B (3) C (4) D (2) B Base your answers to the following questions on the graph below, which shows the solubility (amount that will dissolve in 100 grams of water) of three substances at various water temperatures. Which statement is a correct interpretation of the data in the graph? (1) As water temperature increases, solubility decreases. (2) As water temperature increases, solubility increases. (3) As water temperature increases, solubility increases and then decreases. (4) As water temperature increases, solubility decreases and then increases. (2) As water temperature increases, solubility increases. As the water temperature is increased from 30°C to 70°C, how many more grams of substance A will dissolve in 100 grams of water? (1) 20 g (2) 40 g (3) 50 g (4) 90 g (1) 20 g Which two factors determine the gravitational attraction between two objects? (1) time and temperature (2) shape and orbital speed (3) color and hardness (4) mass and distance apart (4) mass and distance apart Base your answers to the following questions on the diagrams below and your knowledge of science. The diagrams show liquid water changing to water vapor in four different situations. Which observation would be evidence that the water is undergoing a phase change? (4) The water level in the (1) Waves form on the top of the pond. glass of water decreases. (2) Water soaks into the wet sand. (3) The water splashes out of the swimming pool. (4) The water level in the glass of water decreases. The diagram below shows a pinwheel rotating above a lit candle. The arrows indicate the direction of air flow. Which energy transformation is best shown in this diagram? (1) heat to mechanical (2) mechanical to light (3) sound to heat (4) heat to sound (1) heat to mechanical How is heat energy transferred within the liquid water in the pond? (1) compound formation (2) convection currents (3) chemical reactions (4) nuclear reactions (2) convection currents The drawing below shows a person about to lift a book using a ruler and pencil. This drawing illustrates an example of which simple machine? (1) gear (2) pulley (3) balance (4) lever (4) lever Base your answers to the following questions on the information below and on your knowledge of science. A student determined that shaking a container of sand caused the temperature of the sand to rise. The student then performed a new experiment to see if shaking a container of pebbles would cause the temperature of the pebbles to rise. Explain why the shaking caused the temperature of the sand to rise. Shaking the pebbles creates friction which increases the temperature of the pebbles. Write a hypothesis for the new experiment. Identify the dependent (responding) variable in the new experiment. Temperature of the pebbles. Base your answers to thw following questions on information below and on your knowledge of science. Equal-sized pieces of aluminum were placed in test tubes containing equal volumes of acid, at different temperatures. The temperature of the acid in test tube A is 5°C. The temperature of the acid in test tube B is 20°C. What observation would indicate that a chemical reaction is taking place in the test tubes? Bubbles were created when the aluminum mixed with the acid Base your answers to thw following questions on information below and on your knowledge of science. Equal-sized pieces of aluminum were placed in test tubes containing equal volumes of acid, at different temperatures. The temperature of the acid in test tube A is 5°C. The temperature of the acid in test tube B is 20°C. What effect does the temperature of the acid have on the rate at which the reaction progresses? As the temperature of the acid increases, the rate of the reaction also increases. Base your answers to thw following questions on information below and on your knowledge of science. Equal-sized pieces of aluminum were placed in test tubes containing equal volumes of acid, at different temperatures. The temperature of the acid in test tube A is 5°C. The temperature of the acid in test tube B is 20°C. Identify two actions the student could take to increase the reaction rate in the test tubes. 1) Stir the aluminum and acid in the test tube. 2) Break up the aluminum pellet into smaller pieces. Base your answers to the following questions on the information below and on your knowledge of science. A student adds a mixture of oil, sand, and salt to a beaker of water and stirs. The student stops stirring and observes that the salt is no longer visible, the oil floats to the top, and the sand sinks to the bottom of the beaker. Explain why the oil floats after the stirring stops. The oil is less dense than the water so it floats. Explain why the salt is no longer visible after the stirring stops. The salt dissolves in the water. Identify one way to remove the sand from the mixture in the beaker. Use a filter to remove the sand from the water. Water vapor changes to liquid water during which process? (1) dissolving (2) melting (3) evaporation (4) condensation (4) condensation The graph below shows the solubility of two different chemical compounds. Compared to copper sulfate, approximately how many more grams of potassium bromide would dissolve at 90°C? (1) 20 (2) 40 (3) 60 (4) 80 (2) 40 The diagram below shows a stationary cart on a frictionless surface. Two unequal opposing forces are about to be applied to the cart. If the unequal opposing forces are applied to the cart at the same time, what will occur? (1) The cart will move to the left. (2) The cart will move to the right. (3) The cart will alternate between moving left and right. (4) The cart will remain stationary. (2) The cart will move to the right. Some common substances and their chemical formulas are listed in the chart below. Substance Formula Carbonic acid H2CO3 Oxygen O2 Hydrochloric acid HCl Carbon dioxide CO2 Water H 2O Helium He Which of these substances are elements? (1) hydrochloric acid and carbonic acid (2) carbon dioxide and water (3) oxygen and helium (4) water and oxygen (3) oxygen and helium A substance has a freezing point of –38°C and a boiling point of 356°C. At what temperature would this substance be in its liquid state? (1) –100°C (2) –50°C (3) 80°C (4) 375°C (3) 80°C The diagram below shows the steps necessary to produce the energy needed to run a hair dryer. As it moves from location A to location D in the diagram, the energy stored in the coal (1) is converted to solar energy (2) reduces the friction in the hair dryer (3) is recycled (4) is transformed (4) is transformed The illustration below shows an example of energy changing forms. Which changes in energy form are illustrated in the diagram? (1) electrical → sound → light and mechanical (2) sound → mechanical → light and electrical (3) mechanical → light → sound and electrical (4) light → electrical → mechanical and sound (4) light → electrical → mechanical and sound The cartoon below shows a humorous view of a law of motion. Which statement best summarizes the scientific concept shown in the cartoon? (1) A falling body accelerates at a constant speed. (2) The motion of an object is constantly changing due to magnetic forces. (3) The force of friction causes an object in motion to move faster. (4) A body in motion will remain in motion unless influenced by an outside force. (4) A body in motion will remain in motion unless influenced by an outside force. The pie chart below compares the amounts of energy from different sources used in the United States each year. Which two energy sources together provide more than 50% of the energy needs of the United States? (1) nuclear and natural gas (2) hydropower and oil (3) oil and coal (4) natural gas and coal (3) oil and coal A student goes skateboarding a few times a week. The student notices that she can go faster while skating on some level surfaces than on others. She hypothesizes that speed has something to do with the surface she is skating on. The student wants to design an experiment to test this hypothesis. Identify the independent (manipulated) variable in the experiment. The surface she skates on. Identify the dependent (responding) variable in the experiment. The speed the skater can go. Identify two factors that will need to be held constant in the experiment. 1) The force she uses to push the skateboard. 2) The amount of time recorded in the experiment. Base your answers to the following questions on the diagram below. The diagram shows the relative strengths of the gravitational force for planets of different masses. The size of each planet represents the planet's relative mass. The arrow length indicates the relative amount of gravitational pull that each planet would exert on an astronaut in space. What is the relationship between the mass of the planets and the relative strength of their gravitational pull? The greater the mass of the planet, the stronger its gravitational pull. Which three planets shown have less gravitational pull than Earth? 1) Mars 2) Mercury 3) Pluto Base your answers to the following questions on the diagram and information below. A student made a rocket balloon using an inflated balloon, a straw, a long piece of string, two poles, and some tape. It looked similar to the diagram below. Air Balloon On the diagram above draw and label arrows to show the motion of the air and the motion of the balloon that would occur when the student releases the inflated balloon. Why is marking the starting position important if the student wants to calculate the average speed of the balloon? It allows him to measure the total distance covered in the total amount of time. The motion of a Foucault pendulum provides evidence of (1) the Sun’s rotation (2) the Sun’s revolution (3) Earth’s rotation (4) Earth’s revolution (3) Earth’s rotation The wheels and gears of a machine are greased in order to decrease (1) potential energy (2) efficiency (3) output (4) friction (4) friction Sand and iron particles that are similar in size and color are mixed together in a beaker. What would be the best method of separating the particles? (1) Use tweezers to separate them. (2) Use a magnet to separate them. (3) Add water to the mixture. (4) Pour the mixture into a filter. (4) Pour the mixture into a filter. Which action forms a different chemical substance? (1) crushing a rock (2) burning a piece of wood (3) mixing salt and pepper (4) melting an ice cube (2) burning a piece of wood The diagram below shows the geometric structure of a molecule of water (H2O). What do the symbols (1) genetic material (2) chemical bonds (3) cells (4) atoms and represent in the model? (4) atoms The data table below shows the mass of an 800-gram block of ice as it melts to a 600-gram block of ice. Mass of Block of Time Ice (minutes) (grams) 0 800 15 750 30 700 45 650 60 600 If the current rate of melting continues, how many more minutes will be required for the 600-gram block of ice to reach a mass of 400 grams? (1) 15 (2) 30 (3) 45 (4) 60 (4) 60 Which graph shows that more grams of a substance can be dissolved in water as the water temperature increases? (3) Which instrument could be used to determine the volume of an irregularly shaped solid? (4) An object accelerates at 3 meters per second2 when a 10-newton (N) force is applied to it. Which force would cause this object to accelerate at 6 meters per second2? (1) 5 N (2) 10 N (3) 20 N (4) 30 N (3) 20 N The diagram below shows a rock suspended above an overflow container filled with water up to the overflow spout. A graduated cylinder is positioned next to the container to collect water that comes out of the overflow spout. Which property of the rock can be directly determined when the rock is placed in the overflow container? (1) mass (3) volume (2) density (3) volume (4) hardness Which process is an example of a physical change? (1) wood burning (2) iron rusting (3) ice melting (4) milk souring (3) ice melting Which statement best describes the energy changes that occur while a child is riding on a sled down a steep, snow-covered hill? (1) Kinetic energy decreases and potential energy increases. (2) Kinetic energy increases and potential energy decreases. (3) Both potential energy and kinetic energy decrease. (4) Both potential energy and kinetic energy increase. (2) Kinetic energy increases and potential energy decreases. The graph below shows the heating curve for substance X. At approximately which temperature does a phase change begin? (1) - 30°C (2) -10°C (3) 0°C (4) 18°C (4) 18°C All matter is made up of (1) cells (2) atoms (3) molecules (4) compounds (2) atoms The diagram below shows water being heated in a flask. The flask has a rubber stopper with a glass tube extending through it. The current level of the water in the glass tube is indicated. The temperature of the water is 25°C. If heating continues, the water in the glass tube will most likely (1) turn into a solid (2) become more dense (3) move into the flask (4) rise higher in the tube (4) rise higher in the tube The diagram below shows a model of a sample of gas particles at room temperature. Which diagram best shows the results of removing heat from this sample until it freezes? (1) The diagram below shows a spinning water sprinkler. Water comes through a hose and is sprayed by the sprinkler. Which principle best explains why the sprinkler spins? (1) Every action has an equal and opposite reaction. (2) Solid substances are usually more dense than liquid substances. (3) Energy is released when water condenses. (4) Most substances expand when heated and contract when cooled. (1) Every action has an equal and opposite reaction. The gravitational force between the Moon and Earth depends on (1) their masses, only (2) their diameters, only (3) their masses and how far apart they are (4) their diameters and how far apart they are (3) their masses and how far apart they are The diagram below shows a hammer being used by a person to remove a nail from a piece of wood. The hammer is being used as which type of simple machine? (1) wheel and axle (2) inclined plane (3) lever (4) pulley (3) lever A student rubs her hands together on a cold winter day. The heat that warms her hands is produced by (1) friction (2) gravity (3) light (4) magnetism (1) friction When carbon and oxygen combine chemically, the mass of the product is (1) greater than the mass of the carbon plus the mass of the oxygen (2) equal to the mass of the carbon plus the mass of the oxygen (3) equal to the mass of the carbon (4) less than the mass of the carbon (2) equal to the mass of the carbon plus the mass of the oxygen During which phase change is heat energy absorbed by a substance? (1) liquid to gas (2) gas to solid (3) liquid to solid (4) gas to liquid (1) liquid to gas Base your answer to the question on the information below and on your knowledge of science. A baseball strikes the roof of a car and dents it. The paint on the roof begins to crack and chip, exposing the metal. The exposed metal on the roof rusts, eventually causing a small hole in the roof. Which event is a chemical change? (1) The baseball strikes the roof. (2) The roof of the car dents. (3) The paint cracks and chips. (4) The exposed metal rusts. (4) The exposed metal rusts. The diagram below shows a student using a spring scale to pull a wooden block up a ramp that is resting on a stack of books. Which change would require more force to pull the wooden block up the ramp? (1) Have the student use two hands. (2) Reduce the mass of the wooden block. (3) Restack the books so the thinnest book is on the bottom. (4) Glue sandpaper to the surface of the ramp. (4) Glue sandpaper to the surface of the ramp. Water at 20°C in an uncovered pan is evaporating very slowly. What could be done to the water to make it evaporate more quickly? (1) Cover it. (2) Heat it. (3) Place it in the dark. (4) Put salt in it. (1) Cover it. The diagram below shows a Bunsen burner heating a beaker of water on a beaker stand. The arrows represent the transfer of heat energy in the water. Which process is primarily responsible for the transfer of heat indicated by the arrows in the beaker of water? (1) conduction (2) convection (3) radiation (2) convection (4) condensation Which object represents a simple machine? (2) Base your answer to the question on the information and graphs below and on your knowledge of science. Some species of bacteria are harmful. Antibiotics are chemicals that kill bacteria. Some bacteria are resistant to antibiotics and are not killed by these chemicals. Over time, the resistant bacteria can reproduce and create populations that are not affected by antibiotics. The graphs below show the results of a controlled experiment that measured the population of one species of bacteria that had been grown in four containers under identical conditions. Different antibiotics were added to three of the four containers. Which conclusion about this species of bacteria is best supported by the information in the graphs? (1) Antibiotic A continuously slowed the growth. (2) Antibiotic B was least effective in controlling the growth. (3) Antibiotic C was most effective in controlling the growth. (4) Antibiotics A and B slowed the growth. (3) Antibiotic C was most effective in controlling the growth. The control in this experiment is represented by the container with (1) antibiotic A added (2) antibiotic B added (3) antibiotic C added (4) no antibiotic added (4) no antibiotic added Which sequence of energy transformations occurs after a batteryoperated flashlight is turned on? (4) Chemical electrical light The gravitational force between two objects depends on the distance between the objects and each object's (1) mass (2) volume (3) pressure (4) temperature (1) mass Which diagram best represents molecules of matter in the solid phase? (2) Base your answers to following questions on the information and diagram below and on your knowledge of science. During an experiment, a strip of magnesium (Mg) metal wrapped around a nichrome (nonreactive) wire is placed in a flask. The nichrome wire outside the flask is insulated. The contents of the flask are sealed off from the environment with a rubber stopper. When the nichrome wire is connected to a battery, an electric current passes through the wire, causing a white powder called magnesium oxide (MgO) to form. The flask and its contents had a mass of 120 grams before the experiment and a mass of 120 grams after the experiment. Which conclusion can best be made from these measurements? (1) A phase change took place. (2) Energy was destroyed. (3) Matter was conserved. (4) New elements were formed. (3) Matter was conserved. The chemical change that occurred in the flask is most similar to (1) burning a piece of coal (2) freezing water in a container (3) breaking a piece of wood into many pieces (4) bending a wire to form a hook (1) burning a piece of coal The graph below shows the distance traveled by four cars, A, B, C, and D, over a period of time. The average speed of a moving object can be determined by using the equation below. Which car traveled at an average speed of 20 kilometers per hour? (1) A (2) B (3) C (2) B (4) D The diagram below shows a triple-beam balance. What is the maximum mass, in grams, that could be measured by this balance? (1) 110 (2) 500 (3) 610 (4) 1510 (3) 610 A student is trying to dissolve 20 grams of sugar in a beaker containing 250 milliliters of water at room temperature. What can the student do to make the sugar dissolve faster in the water? (1) decrease the temperature of the water (2) use larger pieces of sugar (3) stir rapidly (4) use less water (3) stir rapidly Base your answer to the following question on the portion of the Periodic Table of the Elements shown below and on your knowledge of science. The elements fluorine, chlorine, bromine, and iodine are all found in the same group (17) on the table. These elements are grouped together because they (1) are metals (2) react in similar ways (3) have the same atomic mass (4) are noble gases (2) react in similar ways Water (H2O) is not found on the Periodic Table of the Elements because water is (1) an atom (2) a liquid (3) a mixture (4) a compound (4) a compound The force of an object, with a certain mass accelerating at a certain rate, can be determined by using the equation below. force = mass X acceleration Which object would have the greatest force? (1) a 5-kg object accelerating at 10 m/s² (2) a 5-kg object accelerating at 20 m/s² (3) a 20-kg object accelerating at 4 m/s² (4) a 20-kg object accelerating at 3 m/s² (3) a 20-kg object accelerating at 4 m/s² The diagrams below show two ways of loading a box into a truck. The person using the track with the rollers uses less energy to load the box because the rollers reduce the (1) mass of the box (2) distance traveled by the box (3) force of gravity (4) force of friction (4) force of friction The diagram below shows a sugar cube that has been placed in a container of water. The sugar cube will dissolve in the water. Describe two ways to make this sugar cube dissolve more quickly in the water. (1) Crush the sugar cube. (2) Heat the water. An experiment was conducted to observe the effects of acid on chalk, a form of calcium carbonate. Three pieces of chalk were carved with the same pattern and placed in test tubes A, B, and C. Equal volumes of water were added to test tubes A and B. The student blew through a straw into test tube B for five minutes, producing bubbles. An equal volume of vinegar (acetic acid) was added to test tube C and bubbles were produced. The next day, the student observed and recorded the results shown in the data table below. What was the purpose of test tube A in this experiment? To act as the control for the experiment. Which test tube(s) showed signs of a chemical change? Test tubes B & C Base your answers to the following questions on the diagram below and on your knowledge of science. The diagram shows a model of the water cycle. Explain why the level of the muddy water will decrease slightly if the model is left in a sunny location for several days. Evaporation will cause the muddy water to decrease. What water cycle process is represented by the drops of clean water falling into the glass Precipitation Base your answers to the following questions on the diagrams below and on your knowledge of science. The diagrams show a student using a bow and arrow. The bow string on the bow is used to propel the arrow forward. State one change the student could make, without changing the angle at which the bow is held, so that the arrow would travel a greater distance. Pull the string of the bow back farther. Describe how gravity affects the path of the arrow after it has been released. Gravity will cause the arrow fall to the ground.