Download Final Exam Study Guide Answer Key

Physical Science Final Exam Study Guide – ANSWER KEY
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At the end of an experiment you must draw a conclusion. This step indicates whether the data supports your
hypothesis or not.
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What is a scientific model? A representation of an object or system.
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Once you’ve asked questions and made observations, what is the next step in the scientific method? Form a
hypothesis and test it.
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Measuring something is one way of collecting data.
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What kinds of changes in substances are always physical changes? Changes of state
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How does a physical change differ from a chemical change? In a physical change the composition in unchanged.
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Why is density considered a useful property for identifying matter? Density is unique to each substance
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How could you change the mass of an object? Add or take away matter
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Why is freezing water to make ice considered a physical change? The water only changes state
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What happens to matter during chemical changes? The composition of the matter changes
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How does a basketball under high pressure compare to a basketball under low pressure? It contains more gas
particles.
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The melting point of salt is the same as its freezing point.
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How do the particles of water that evaporate from an open container differ from the particles that remain? The
particles that evaporate (gas) have more energy and more speed than the particles that remain (liquid).
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How do elements join to form compounds? In a specific mass ratio
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How are metalloids similar to metals? Some are shinny and/or good conductors of electric current
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How can a compound be broken down? By a chemical change/chemical reaction
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Explain the difference between speed and velocity? Velocity includes direction and speed does not.
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As the distance between two objects increases, the force of gravity between them decreases.
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What is the net force on an object when you combine a force of 10 N north with a force of 5 N south? 5 N north
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What does the law of universal gravitation state? Gravitational force is related to mass and distance
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What is an object that appears to stay in place that helps you detect motion in another object? Reference point
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Which is an example of friction that is helpful? Answers will vary
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When something changes position, what is it doing? moving
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Why does a crumpled piece of paper hit the ground before a flat sheet of paper? Crumpled paper has less air
resistance
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According to Newton’s first law of motion, a moving object that is not acted on by an unbalanced force will do what?
It will remain in motion/keep moving until another unbalanced force acts on it.
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A cue ball rolls toward a billiard ball with a velocity of 1.0 m/s east. Both balls have identical masses. What happens
to the total momentum after the two balls collide? The momentum will remain the same.
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List examples of action/reaction pairs. Answers will vary
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If the work output of a machine is always less than the work input, where does the missing work go? It is used to
overcome friction.
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List examples of compound machines. Answers will vary
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What does a fixed pulley change? The direction of the applied force
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What is a machine with a grooved wheel that holds a cable? pulley
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What type of energy comes from a compound that changes as its atoms are rearranged? Chemical energy
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Whenever one form of energy is converted into another, some of the original energy is always converted into which
type of energy? Thermal energy
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When you eat fruits and vegetables, what type of energy are you taking in? Chemical energy
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What do you call the energy of motion? Kinetic Energy
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What is the purpose of insulation? Prevents the unwanted transfer of thermal energy into or out of a building.
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The transfer of thermal energy through a substance by direct contact is called thermal conduction.
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In both hot-water and solar-heating systems, the thermal energy from heated water circulates through the air of a
room by convection.
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How would you describe the nucleus of an atom? It is small, dense, and positively charged.
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Which of the subatomic particles has the least mass? electrons
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What did Bohr, Democritus, Thomson, Dalton, and Rutherford all have in common? They all contributed to the
development of the atomic theory.
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What is an isotope? An atom that has the same number of protons as other atoms of the same element do but
that has a different number of neutrons.
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What does periodic mean? Happening at regular intervals
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Each vertical column on the periodic table is called a(an) group.
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Mendeleev arranged the elements by increasing atomic mass.
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What are most of the elements in the periodic table? metals
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What can group numbers on the periodic table help you determine? The number of valence electrons
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How are electrons in an atom organized? In energy levels
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What is the joining of atoms to form new substances? Chemical bonding
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What is the most important factor in determining how an atom will bond? The number of electrons in the
outermost energy level (valence electrons).
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What are the properties of metals associated with metallic bonds? Malleability, ductility, conductivity
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What are some signs that provide PROOF that a chemical reaction has taken place? A new substance is formed
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What is the force that holds atoms together called? Chemical bond
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A calcium carbonate molecule has 1 calcium (Ca) atom, 3 oxygen (O) atoms, and 1 carbon (C) atom. What is the
chemical formula for calcium carbonate? CaCO3
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What is the rate at which electrical energy is changed into other forms of energy? Electric power
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What does the amount of energy released per charge depend upon? voltage
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What goes down as resistance goes up? current
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What determines whether a material is magnetic or not? The arrangement of the atoms
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In a solenoid, what would result in a stronger magnetic force? Increasing the number of loops in the coil,
increasing the strength of the electric current, and adding an iron core.
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What causes an echo? Reflection of a sound wave
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How is a standing wave formed? Through interference of sound waves.
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What is the amplitude of a wave related to? The height of the wave.
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What unit is used to describe the frequency of a wave? Hertz
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What can a violinist do if one string is producing a sound that is too low? Shorten the string of the violin
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Sound waves are best reflected off which surfaces? Smooth, hard surfaces
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What does the mixing of pitches through interference produce? The sound quality
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What wave interaction occurs when waves combine and the resulting wave has a greater amplitude than the individual
waves had? Constructive interference
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What wave interaction occurs when waves combine and the resulting wave has a smaller amplitude than the
individual waves had? Destructive interference
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The amount a wave diffracts depends on its wavelength and the size of the barrier or opening.
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What determines the colors of translucent and transparent objects? The color of light they transmit
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What is an electromagnetic wave? A wave that consists of changing electric and magnetic fields.
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The major source of energy on Earth originates from waves from the sun.
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What kinds of waves are used in radar for detecting the speed of a car? Microwaves
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The amount a wave diffracts depends on what? Wavelength