Name:______Date:______
Class #:______
Grade 7 Science: Benchmark #1 CHEMISTRY
Part A: Multiple Choice (10 points)
Please write the number for the correct answer on the line provided
______1. All matter is made up of particles called
(1) cells (2) atoms(3) molecules (4) compounds
______2. Which diagram best represents molecules of matter in the solid phase?
______3. The number of protons in an atom is equal to the number of
(1)Isotopes (2) Atomic Number (3) Electron Orbits
______4. The negatively charged part of an atom is
(1)Proton (2) Neutron (3) Electron
______5. 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?
______6. What is a property of a metal?
(1)Dull(2) Shiny(3) Poor conductor of heat
______7. What is the phase change from a solid to a liquid?
(1) Sublimation (2) Evaporation (3) Freezing (4) Melting
______8. The diagram below shows the structure of a molecule of water (H2O).
Represent Oxygen. What does the represent in the model?
(1) hydrogen (2) cells (3) chemical bonds (4) oxygen
______9. How do the particles of a gas behave?
(1)Move slowly (2) Move very fast (3) Vibrate in place
______10. Which scientific tool could be used to predictthe properties of an element?
(1) barometer
(2) pulley
(3) Periodic Table
(4) water cycle chart
Short Answer (20 Points)
Please write your answers in complete sentences on the lines provided
Thediagram shows a sequence of events. The ball and ring are made of the same metal.
11. State the relationship between the temperature of the metal ball and the speed of the molecules moving in the ball. [2]
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Record your answers in the spaces provided below each question.Base your answers to question 12on the passage below and on your knowledge of science.
A student adds sugar to a cup of iced tea and a cup of hot tea. She notices that the timeneeded for the sugar to dissolve in each cup is different. She thinks this has something to dowith the temperature of the tea. She wants to design an experiment to see if she iscorrect.
12. Write a hypothesis based on the student’s observations. [2]
______
13. The diagram below shows an activity performed by a student in a classroom.
Complete the chart below by identifying one phase change that is occurring at each location. [4]
Base your answers to questions 14 on the diagram below and on your knowledge of science.
The diagram shows a phase change represented by letter A.
14. State the term for the phase change that occurs at A. [1]
______
Base your answers to questions 15 through 17 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 studentstops stirring and observes that the salt is no longer visible, the oil floats to the top, andthe sand sinks to the bottom of the beaker.
15. Explain why the oil floats after the stirring stops. [1]
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16. Explain why the salt is no longer visible after the stirring stops. [2]
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17. Identify one way to remove the sand from the mixture in the beaker. [2]
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Base your answers to questions 18 through 19 on the information below.
Models are often used to explain natural phenomena. Develop a model to show therelationship between heat energy and the motion and position of particles in a sample ofmatter. Use a group of 20 students in an empty room to represent the particles in a sample
of matter.
18. How should the students be placed in the room to represent the arrangement of particles in a solid? [2]
______
19. 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.] [2]
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Base your answers to question 20 on the diagram below and on your knowledge of science. Thediagram shows a glass partially filled with water and ice cubes.
20. Explain why water droplets have formed on the outside of the glass. [2]
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BONUS
What evidence in the diagram from question 20 indicates that ice has a lower density than water? [1]
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