Transformations and Flow of Energy Within A System

Which BEST describes chemical energy?

• energy stored in the nucleus of atoms

• energy due to the movement of electrons

• energy stored in bonds between atoms and molecules

• energy due to the motion of atoms and molecules within substances

Which example BEST demonstrates the conversion of nuclear energy into electrical energy?

• Friction of water molecules in a cloud causes a large buildup of electrons in one area. When the voltage is large enough, a lightning bolt occurs.

• In a hydro-electric dam, a large amount of water molecules flows downward from a water reservoir, turning turbines that generate electricity.

• A fully charged battery is attached to a closed electrical circuit, causing electrons to flow through the circuit.

• A reactor generates heat by splitting uranium, creating steam that turns turbines to generate electricity.

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NGSS.HS-PS3-4

What is the sequence of energy transformations occurring in Iceland?

• Thermal energy is transformed into electrical energy, which is transformed into mechanical energy.

• Thermal energy is transformed into mechanical energy, which is transformed into electrical energy.

• Chemical energy is transformed into electrical energy, which is transformed into mechanical energy.

• Chemical energy is transformed into mechanical energy, which is transformed into electrical energy.

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NGSS.MS-ESS3-1

NGSS.MS-PS1-4

Paul is investigating the effect of heat on gases. He pours 1 inch of water in a pan and places it on a stove. He then secures a balloon over the mouth of a 2-liter glass bottle and places it in the pan. He heats the pan until the water boils. After ten minutes, Paul transfers the bottle to another pan with ice water. Investigation Setup: Step 1: Balloon inflates (Pan with hot water) Step 2: Same bottle and balloon from Step 1 (Pan with ice water) Which of the following statements should Paul use as his conclusion from the experiment?

• As air in the bottle is heated, the electrons in air atoms emit heat energy all the way to the top causing the balloon to inflate. As air is cooled, the electrons radiate heat outside the balloon causing it to deflate.

• As air in the bottle is heated, the molecules of air move faster and expand, so they rise and inflate the balloon. As air is cooled, the molecules slow down causing the air to contract, deflating the balloon.

• In step 1, warmer air molecules heat cooler air molecules until all the heat travels to the top and enters the balloon. In step 2, cooler air molecules cool off warmer molecules, so that all heat gets out of the balloon.

• In step 1, the heat causes the air molecules to expand and grow, making them to occupy the balloon and inflating it. In step 2, air molecules are cooled, so they return to their normal size, and the balloon deflates.

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NGSS.MS-PS1-4

Which of the following is a reliable investigation to study how heat is transferred by conduction?

• Investigating why the water in a pool heats up as the sun shines on it.

• Investigating why the upstairs of a house is warmer than the basement.

• Investigating why the handle of a pot will heat up as food is cooking over an open fire.

• Investigating why the bottom of a loaf of bread browns faster than the top of a loaf of bread as an oven temperature is increased.

Anne was informed that a snow storm will soon arrive and decided to investigate how thermal energy transfers in objects outside her house. Anne knew that those objects that will be able to transfer thermal energy faster will have less snow accumulated on top of them because it will melt. She bought two identical mailboxes and painted one gray and one black. Which mailbox will have LESS snow remaining after the Sun comes out following the storm and why?

• Both the black and gray mailbox will have the same amount of snow because the absorption of infrared radiation is not affected by the color.

• Both the black and gray mailbox will have the same amount of snow because the absorption of ultraviolet radiation is not affected by the color.

• The gray mailbox because the gray paint absorbs more heat and the molecules of the gray surface vibrate faster than those of a black surface.

• The black mailbox because the black paint absorbs more heat and the molecules of the black surface vibrate faster than those of a gray surface.

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NGSS.MS-PS1-4

When does the addition of heat result in a rapid temperature rise?

• When the material has a low latent heat of vaporization.

• When the material has a high latent heat of vaporization.

• When the material has a low specific heat.

• When the material has a high specific heat.

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NGSS.MS-PS1-4

NGSS.MS-PS3-4

Based on the table, which substance would be the BEST conductor of thermal energy and why?

• chromium; because it is a transition metal with the highest specific heat value

• copper; because it is a transition metal and is used in plumbing for hot water lines

• iron; because it is a transition metal that is widely used in construction materials

• silver; because it is a transition metal with the lowest specific heat value

What types of materials are good thermal insulators and why?

• Metals are the best thermal insulators because less heat energy is needed to cause them to increase in temperature.

• Metals are the best thermal insulators because more heat energy can be stored without causing their temperature to increase.

• Non-metals are the best thermal insulators because less heat energy can be stored without causing their temperature to increase.

• Non-metals are the best thermal insulators because more heat energy is needed to cause them to increase in temperature.

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NGSS.MS-PS3-3

NGSS.MS-PS3-4

Kinetic energy in the form of heat increases the motion of the molecules. Regions B and D of the heating curve represent segments of the curve where heat is being added, but the temperature is not changing. Which of the following is the BEST explanation for regions B and D of the curve and why?

• The substance freezes or condenses because it is undergoing an exothermic phase change.

• The substance melts or boils because it is undergoing an endothermic phase change.

• The substance sublimes or deposits because it is undergoing an exothermic phase change.

• The substance freezes or boils because it is undergoing an endothermic phase change.

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NGSS.MS-PS1-4