7th Grade Integrated Science Unit Review – Earth Matters and Density
Use notes, labs, and science book to find the answers to these questions: You will use pages 60-74 of your book)
CONCEPT 1: DENSITY
1. Density is the amount of matter in a certain amount of a substance. It is given in a comparison of x FOR EVERY y.
2. Know the formulas for density, mass, and volume. Know how to solve for each! You may use a calculator. You
can use either of the following.
3. Density applies to any substance that can be mixed with each other. The higher the density, the more they will sink.
Know how to apply this to real life situations: 1) Combination of three liquids 2) throwing objects into water 3)
comparison of two solids. See page 60 for more information. Examples are given on page 74.
4. Archimedes’ principle (see page 61)
Part 2: The sorting of Earth’s materials6. Explain why a hot air balloon rises through the air around it?
11. What three factors determine how particles are sorted in a stream?
12. Where will the largest particles in a stream be deposited?
13. Where will the smallest particles in a stream be deposited?
14. What is the force that causes particles to sort by density?
15. List the main layers of the earth
16. What is the state of matter for each of the layers of the earth? What is unique about the mantle?
17. Based on what you have learned about expansion and contraction of particles when heated, why do you think the
inner and outer core are similar in composition and temperature, but the inner core is solid and the outer core is liquid?
18. List the main materials found in each of the earth’s layers.
19. Give average density for each of the earth’s layers
20. Why do you think the layers of the earth are separated by density?
21. Explain how convection currents work.
22. What is the main gas that makes up earth’s atmosphere?
23. Explain how scientists use earthquakes and meteorites to learn about the interior of the earth.
24. How are models of the earth helpful to scientists?
25. Based on what you have learned about models, what do you think some of the limitations are for models of the
earth?
KNOW THE FOLLOWING TERMS: (See page 73 in your textbook)
Atmosphere – The layers of air that surround Earth.
Crust – The solid outer layer of earth where life is found. Thinnest layer.
Density – A comparison of the Mass and Volume of an object. KNOW THE FORMULA: D= M/V
Inner Core – The centermost layer of the earth. The hottest and most dense.
Mantle – A semi-solid layer of Earth that takes up themost volume of earth.
Mixture – A combination of two substances that have not chemically combined.
Model – A diagram, or representation of an object or process used to teach a concept or idea. Models are best for one
or two ideas and are limited because they do not always show detail or scale.
Outer Core- A liquid layer of Earth found near the center. Between the Mantle and Inner Core. Made of metal.
Particle – A small piece of something, typically used to represent a small part of matter.
Seismic Waves – Waves that are generated by earthquakes and used to explain the states of matter and density of
earth’s interior layers.
Sorting – the process that separates particles baed on differences in density and/or size.