Tasc Science Exam 3

D. The conversion between feet and mile is a unit conversion in the English system. Within this system, 5,280 feet is equivalent to 1 mile. See Lesson: Temperature and the Metric System.

A. The control variable is a standard or constant that is used for comparisons. See Lesson: An Introduction To Biology.

C. A pH scale is used as an indicator and to determine the strength of an acid or a base. Acidic solutions have a pH less than 7, and basic solutions have a pH greater than 7. Neutral solutions have a pH equal to 7. See Lesson: Acids and Bases.

A. A material, such as many metals, that allows current to flow freely through it is called a conductor. See Lesson: Electricity and Magnetism.

D. As with electric charge, like magnetic polarities repel and unlike polarities attract. In this case, the magnets will experience an attractive force that pulls them together. See Lesson: Electricity and Magnetism.

C. The mass is determined by adding the numbers of protons and neutrons (17 + 20 = 37). See Lesson: Scientific Notation.

C. The electrons are found in the lowest possible shells. Only 2 can fit in the first shell, and only 8 can fit in the second shell. Filling those levels accommodates 10 electrons. The remaining 3 electrons will go into the third shell. See Lesson: Scientific Notation.

B. As particles condense, the substance turns from gas to liquid. The particles of liquids are closer together than the particles of gas. See Lesson: States of Matter.

A. The pH scale is used to determine the strength of an acid or base. On a scale from 1 to 14, any pH value greater than 7 is basic. The closer the pH is to 14, the stronger the base. See Lesson: Acids and Bases.

A. The volleyball is moving, so it has kinetic energy. It is above ground level, so it also possesses potential energy. See Lesson: Kinetic Energy.

B. There are 2.54 centimeters in 1 inch. Dividing 35 by 2.54 converts 35 centimeters to 13.77 inches. See Lesson: Temperature and the Metric System.

C. Plant cells are autotrophs that harness energy from the sun and use it to make food. This process of using energy to make food is done with the help of photosynthesis. See Lesson: Cell Structure, Function, and Type.

C. The replication of DNA ends with a twisted strand called a double helix. See Lesson: Genetics and DNA.

A. Like charges repel, so if the experimenter knows the charge polarity of one object (positive), he knows that the other object has the same charge polarity if they exert a repulsive force on each other. See Lesson: Waves and Sounds.

B. A stopwatch is a device used to record time in an experiment. See Lesson: Designing an Experiment.

B. Biology is the study of life; it examines how living things function and survive. Because fish and algae are living things, this is a biological study. See Lesson: An Introduction To Biology.

C. Homeostasis is common to all living things, so this trait can be used to differentiate a living thing from a nonliving thing. See Lesson: An Introduction To Biology.

A. Because gold has the highest melting point, it would take more energy to melt it than to melt lead or mercury. If a substance has a relatively high melting point, it is because the forces holding the particles together are relatively strong. See Lesson: States of Matter.

C. Mechanical waves involve oscillation of some material, such as water or air. Choices A, B, and D are electromagnetic waves—they can travel in the absence of a material. Seismic waves travel through solids and liquids as a result of geological events. See Lesson: Waves and Sounds.

A. The AgCl is the only compound in this equation that is not in an aqueous solution. Instead, it is a solid that does not dissolve in the solvent in which the reaction is occurring. See Lesson: Chemical Solutions.

A. At 0°C, about 18 grams of Ce₂(SO₄)₃ can dissolve in 100 grams of water, and at 100°C, around 4 grams can dissolve. See Lesson: Chemical Solutions.

B. After a hypothesis is formed, variables are created when experiments are designed to test the hypothesis. See Lesson: Designing an Experiment.

C. This silver isotope has a mass number of 109. Silver has 47 protons, which contribute 47 to the mass number. To get the number of neutrons, subtract: 109 – 47 = 62. This atom contains 62 neutrons. See Lesson: Scientific Notation.

C. The process that rewrites the information in a gene in DNA into a molecule of messenger RNA is called transcription. See Lesson: Genetics and DNA.

B. Black coffee is a substance because each sip of the substance contains the same ingredients. See Lesson: Properties of Matter.

A. To multiply a scalar and a vector, multiply each coordinate of the vector by the scalar. Then, add the resultants by adding their respective coordinates:



See Lesson: Nature of Motion.

B. The centrifugal force, which is a “ghost force,” is the feeling of being pushed in a certain direction when undergoing rotational motion. The centripetal force, which is a real force, is always in the opposite direction. Thus, if the pilot feels an upward force, the centripetal force must be downward, making answer B correct. See Lesson: Friction.

C. The appearance of a bent straw in water is due to the bending of light as it transmits from one material to another when those materials have different indices of refraction—in this case, water and air. Refraction is the wave behavior that explains this effect. See Lesson: Waves and Sounds.

D. Because the type of car used during the experiment is not manipulated, this is a type of control. See Lesson: Designing an Experiment.

D. An animal cell is a eukaryotic cell, which means it lacks a flagellum. Unlike plant cells, which have chloroplasts and a cell wall, animal cells contain a Golgi apparatus. See Lesson: Cell Structure, Function, and Type.

C. An object undergoing projectile motion maintains a constant horizontal velocity unless some force acts on it. The force in this case is friction due to air resistance. See Lesson: Friction.

B. Basic substances turn litmus paper blue. Because KOH is a strong base, it will turn litmus blue. See Lesson: Acids and Bases.

C. Impulse and momentum and directly proportional. See Lesson: Kinetic Energy.

D. All four compounds contain chlorine atoms. All chlorine atoms make one bond, sharing two electrons, with another atom. See Lesson: Chemical Bonds.

B. In the graph, the line for 30 grams of solute crosses the line for KClO₃ at 70°C. See Lesson: Chemical Solutions.

A. An object subject to no net force will have a constant velocity, meaning its motion is linear. If it is subject only to friction, the net force will be opposite to the velocity, as will the acceleration vector. Although the object will decelerate, its direction of motion will remain the same. Its motion will therefore be linear. See Lesson: Friction.

C. Ions are electrically charged particles, so they have electric fields associated with them. Also, since they are accelerating, they produce both magnetic fields and electromagnetic waves. Because they are moving in a vacuum, however, they have no medium in which to produce mechanical waves. See Lesson: Electricity and Magnetism.

C. After a protein is synthesized, it goes to the Golgi apparatus where the protein is further modified and then packaged for transport in the cell. See Lesson: Cell Structure, Function, and Type.

C. After glycolysis occurs to make pyruvate, this molecule must be converted into acetyl coA to enter the citric acid cycle in the mitochondrial matrix. See Lesson: Cellular Reproduction, Respiration, and Photosynthesis.

D. During anaphase, the chromosome is pulled apart by spindle fibers that are attached to the centromeres of the chromosome. This causes the chromosome to split into two sister chromatids. See Lesson: Cellular Reproduction, Respiration, and Photosynthesis.

C. The standard form of a vector is the head coordinates minus the tail coordinates. In this case, the head coordinates are unknown. Start by writing an expression for the vector. Let the head coordinates be (x, y), for example.



(2, 6) = (x – 3, y – 1)



Solve the two equations for x and y:

x – 3 = 2

x = 5



y – 1 = 6

y = 7



See Lesson: Nature of Motion.

A. The RNA molecule is released into the cell for the next stage. See Lesson: Genetics and DNA.

B. Any substance will condense and boil at the same temperature, assuming these processes are carried out under the same conditions. This is the temperature at which the substance transitions between liquid and gas states. See Lesson: States of Matter.

C. Intensive properties do not depend on the amount of matter that is present. See Lesson: Properties of Matter.

C. Intensive properties do not depend on the amount of matter that is present. Intensive properties do not change according to conditions. See Lesson: Properties of Matter.

A. Barium is in group 2 and has two valence electrons. Losing those two valence electrons will result in a stable barium ion with a charge of +2. See Lesson: Chemical Bonds.

B. Fluorine is farther to the right in the periodic table, which means it has a higher electronegativity than the other elements in period 2. Therefore, it will pull harder on electrons it shares with nitrogen, forming the most polar bond. See Lesson: Chemical Bonds.

B. The final process in cellular respiration, the electron transport chain, yields the largest amount of ATP for a cell. Chemiosmosis, which involves the creation of a proton gradient (with the help of NADH and FADH), is part of this step for cellular respiration. See Lesson: Cellular Reproduction, Respiration, and Photosynthesis.