Marking Period 1 Unit Test Review Properties of Matter Calculate the density of each unknown substance. Density = Mass/Volume Mass Volume Density 3
Unknown (g) (cm ) (g/cm3) 1 10 5 2 2 0.2 100 0.002 3 5 5 1 4 12 2 6 5 28 14 2 Density is an identifying characteristic of a pure substance. If all of the unknowns are pure substances, which two unknowns are probably the same substance? Explain your answer. Unknowns 1 and 5 are probably the same substance because they have the same density of 2 g/cm3. Density is an identifying property of pure substances and unknowns 1 and 5 are both pure substances. The density of water is 1 g/ml. Which of the substances is probably water? Explain your answer. Unknown 3 has a density of 1 g/cm3. Because 1 g/cm3 is the same a 1 g/ml, unknown 3 is probably water. One of the substances is a gas. Based on an analysis of density, which one is most like the gas? Explain your answer. Unknown 2 has a very low density. If only one of the substances is a gas, then the one with the lowest density is most likely the one that is a gas. What is the volume of the tissue paper hot air balloon shown to the right? Include the unit of measure in your answer. 19 cm X 19 cm X 19 cm = 6,859 cm3 What temperature scale is based on absolute zero? Explain. Kelvin is based on absolute zero instead of the freezing point of water. Has any substance on Earth reached absolute zero? Explain. No substance on Earth has reached absolute zero. There is always a transfer of heat that keeps atoms vibrating. Marking Period 1 Unit Test Review Behavior of Gases Look carefully at the graph of a gas experiment. The independent variable is temperature. The dependent variable is pressure. The constants are volume and number of molecules of the gas. What conclusion can be made regarding the relationship between pressure and temperature of a gas as shown on the graph? The opening of a bottle of air was covered with a deflated balloon. The bottle was placed in hot water. The balloon inflated. Explain what why the balloon inflated. Heat was transferred to the gas molecules in the bottle. Hot gas molecules spread out and become less dense. They will rise up into the balloon expanding the space in which they move. The volume increases. What are the two constants? The two constants are pressure and number of molecules of gas. What is the relationship between volume and temperature of a gas? The volume of a gas is directly proportional to the temperature of the gas. Which graph correctly shows the relationship? None of the graphs shows the relationship, because the graphs show pressure dependent on temperature, but the experiment is volume dependent on temperature. If the bottle were capped, then pressure would increase with temperature as shown in graph 1. However, because the balloon expands the volume, pressure remains constant. Marking Period 1 Unit Test Review ­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­ Which graph correctly shows the relationship between pressure and volume of a gas? A (NOTE: The graphs do not go with with the diagram.) Complete the statement based on the information in the diagram. As the pressure increases, the volume decreases. The volume is inversely proportional to the pressure on a gas. ­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­ Tissue paper is denser than air. Why can a tissue paper balloon filled with hot air rise and float in a cold room? The hot air in the balloon is less dense than the colder room air. If the difference in density is great enough, the upward buoyant force will be greater than the downward gravity force. Heat Transfer, Electromagnetic Spectrum, and Atmosphere Heat transfer through a fluid is an example of convection. Heat transfer between two objects in direct contact is an example of conduction_. Heat transfer by electromagnetic waves is an example of radiation. Complete the table. Example Type of Heat Transfer marshmallow toasted by a flame radiation on the side, convection is above, conduction if touching the flame air rising above hot sand convection metal pan on an electric stove burner conduction sunshine striking a blacktop surface radiation water vapor rising in boiling water convection What part of the electromagnetic spectrum is measured as thermal energy? (Hint: You used this type of thermometer to measure surface temperatures.) Part of the infrared spectrum is thermal energy felt as heat. Marking Period 1 Unit Test Review The blocks have the same length, width, and height. Both blocks are next to each other on the same table and have been stored at room temperature. The metal feels colder to the touch than the plastic. Why? Metal is denser than plastic. Heat transfer faster from the finger to the metal than from the finger to the plastic. This makes the metal feel colder than the plastic. Why did the ice cube melt faster on the metal block than on the plastic block? Heat transfers faster through denser materials because the molecules and atoms are closer together. Conduction is heat transfer from molecule to atom by contact. Classify the following as heat conductor or heat insulator. Substance Conductor or Insulator Wood block insulator Wool sock insulator Aluminum can conductor Styrofoam peanuts insulator Glass jar insulator Copper cup conductor ­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­ Which color has the longest wavelength? red Which color has the highest frequency? violet What is the relationship between wavelength and frequency? As the wavelength decreases, the frequency increases. What part of the electromagnetic spectrum is white light? visible light ­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­. Why does the temperature in the troposphere decrease with altitude? Air density decreases with altitude. Why does the temperature increase with altitude in the stratosphere? Ozone formation by ultraviolet radiation emits heat. Why does the temperature in the mesosphere decrease with altitude? The distance from the ozone layer increases with altitude. What part of the electromagnetic spectrum is absorbed in the process of forming the ozone layer? Part of the ultraviolet spectrum is absorbed. Why does pressure continuously decrease with altitude through Earth’s atmosphere? There are fewer and fewer molecules pushing downward on a given surface area. Where in Earth’s atmosphere is water in the liquid phase? Why? Marking Period 1 Unit Test Review Water is liquid in the troposphere because that is where temperatures are above the freezing point of water.