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Matter and Its Properties Chapter Problems
What is Matter?
Class Work
1. If you have one atom of Oxygen and you break it in half, would you still have
Oxygen? Explain.
2. What subatomic particle has a positive charge?
3. What subatomic particle has a negative charge?
4. Fill in the blank of this common phrase that applies to the subatomic particles:
“____________________ attract.”
5. What two subatomic particles are found in the nucleus of the atom?
Homework
6. How do we define “matter?”
7. Can you think of anything that is not matter?
8. What does it mean for a substance to be a “pure substance?”
9. What subatomic particle has a neutral charge?
10. Where are electrons found in the atom?
How Do We Measure Matter?
Class Work
11. List the units of measurement for each of the following:
a. Mass
b. Weight
c. Volume
12. Finish the sentence: Weight depends on ___________________.
13. If you were to go to each of these locations, would you weigh more or less:
a. Moon
b. Jupiter
c. Mercury
Homework
14. How many grams would be in 10 kilograms?
15. A block has a mass of 10 kg on Earth and a weight of 60 lbs. What would its mass
and weight be on the moon?
16. A box has a length of 10 cm, a width of 8.5 cm and a height of 5.5 cm. What is its
volume?
17. Explain how you find the volume of an irregular object.
18. An irregular object is placed in 50 mL of water and the water level rises to 72 mL.
What is the volume of the object?
Elements of the Periodic Table
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7th Grade PSI
Matter and Its Properties
Class Work
19. What did Mendeleev use to organize his first Periodic Table of Elements?
20. What is the symbol for the Magnesium?
21. Which element is represented by the symbol C?
22. What period is Hydrogen (H) located in?
23. What group is Sulfur (S) located in?
24. Pick another atom with similar characteristics for each of these elements:
a. Fluorine (F)
b. Oxygen (O)
Homework
25. How is the modern Periodic Table of Elements arranged?
26. Use your Periodic Table to answer the following questions about Helium (He):
a. Atomic number?
b. Element symbol?
c. Atomic mass?
d. Number of protons?
e. Period?
f. Group?
g. Number of electrons in outer shell?
27. Suppose an element had an atomic number of 52. How many protons would that
element have?
28. Using your Periodic Table, what element has an atomic number of 65?
29. Using your Periodic Table, which element has more protons: Nickel or Iodine? How
do you know?
30. Which element is represented by the symbol W?
31. What period is Silver (Ag) located in?
32. What group is Xenon (Xe) located in?
33. Pick another atom with similar characteristics for each of these elements:
a. Potassium (K)
b. Krypton (Kr)
c. Strontium (Sr)
d. Gold (Au)
Physical Properties
Class Work
34. Explain why metal would be a good choice of material for each of these products:
a. Cooking pot
b. Power lines
c. Horseshoe
d. Refrigerator door
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35. Why are Lanthanides and Actinides placed at the bottom of the Periodic Table of
Elements?
36. What are some physical properties of nonmetals?
37. What do we call the little number after each element symbol in a chemical formula?
What does this number represent?
38. What is the ratio of Sodium (Na) to Chlorine (Cl) atoms in the chemical formula
NaCl? _________
39. The molecule commonly known as Acetylene (C2H2) is made up of what types of
atoms (and how many of each)?
Homework
40. What are common physical properties of most metals?
41. Write the name of the family that is described in a-g:
a. Does not react with other elements
b. End in –ine
c. React by losing 2 electrons
d. Poor conductor of electricity
e. 1 electron in the outer shell
f. Contains many unstable elements that do not occur naturally on earth
g. Can be mixed with other metals to make alloys
42. A _____________ is a pure substance that is made of two or more elements that are
chemically combined in a set ratio.
43. What is the difference between an atom and a molecule?
44. Draw a water molecule.
45. The ratio of Carbon to Oxygen atoms in Carbon Dioxide is 1:2. How would you write
its formula? _________________
46. The molecule commonly known as Nutrasweet (C14H18N2O5) is made up of what
types of atoms (and how many of each)?
Density
Class Work
47. What is the density of a piece of wood that has a mass of 25.0 grams and a volume
of 29.4 cm3?
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48. I threw a plastic ball in the pool for my dog to fetch. The mass of the ball was 125
grams. What must the volume be to have a density of 0.500 g/mL? (I want it to float
of course!)
49. What is the mass of a 12 cm3 sample of pure silicon with a density of 9 g/cm3?
Homework
50. The volume of a solution was measured in a graduated cylinder as 55 mL. If the
mass of the solution is measured to be 70.25 grams, what is the density of the
solution?
51. A piece of wood that measures 3.0 cm by 6.0 cm by 4.0 cm has a mass of 80.0 grams.
What is the density of the wood? Would the piece of wood float in water?
(Volume = L x W x H)
52. A cup of gold-colored metal beads was measured to have a mass of 425 grams. By
water displacement, the volume of the beads was calculated to be 48.0 mL. Given
the following densities, identify the metal:
a. Gold: 19.3 g/mL
b. Copper: 8.86 g/mL
c. Bronze: 9.87 g/mL
53. An ice cube measuring 5.80 cm by 5.80 cm by 5.80 cm has a density of 0.917 g/cm3.
What is the mass?
54. Gasoline is a liquid that will float on water. 450 grams of gasoline is spilled into a
puddle of water. If the density of the gasoline is 0.665 g/mL, what was the volume
of the spilled gasoline?
55. The density of aluminum is 2.70 g/mL. If the mass of a piece of aluminum is 244
grams, what is the volume of the aluminum?
States of Matter
Class Work
56. Compare and contrast solids and gases. What are some characteristics of a solid
that makes it easy to hold as compared to a gas?
57. How do crystalline and amorphous solids differ?
58. How are liquids and solids alike? How are they different?
Homework
For #59-61, provide the following information:
a) Definite or Indefinite Shape?
b) Definite or Indefinite Volume?
c) Easy or Hard to hold in your hand?
d) Particles do or do not move past each other?
e) Fluid or Not a Fluid?
59. Solid
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60. Liquid
61. Gas
62. What is the definition of a fluid? How does it relate to liquids and gases?
63. What would you expect to happen to the shape of a solid object if you put it in a
sealed box?
64. What would you expect to happen to the shape of a liquid if you put it in a sealed
box?
65. What would you expect to happen to a gas if you put it in a sealed box?
Changes of State
Class Work
For #66-67, plot and label 0 °C, the melting point (MP), the boiling point (BP), and room
temperature (RT, 20 °C) on a number line. Then, identify what state of matter the
substance would be at room temperature.
66. Argon
MP -189 °C
BP -186 °C
67. Beryllium
MP 1287 °C
BP 2471 °C
68. What is the difference between a substance’s melting point and its freezing point?
69. What differences are there between the two types of vaporization?
Homework
70. What happens to the amount of energy when temperature is raised? What does this
do to the particles that make up an object?
71. How can you tell that water is boiling? How can you tell that water is evaporating?
72. For a-d, write E if the sentence is referring to Evaporation and C if it is referring to
Condensation:
a. A substance changes from a liquid to a gas.
b. More molecules are breaking free from a liquid than joining it.
c. More molecules are joining together with a liquid rather than leaving it.
d. Molecules of water vapor are colliding and sticking together in the air.
For #73-78, identify the state of matter of the substances below at room temperature. Plot
and label 0 °C, the melting point (MP), the boiling point (BP), and room temperature (RT,
20 °C) on a number line.
73. Mercury
74. Nickel
75. Silicon
76. Bromine
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MP -39 °C
MP 1455 °C
MP 1414 °C
MP
-7 °C
7th Grade PSI
BP 357 °C
BP 2913 °C
BP 3265 °C
BP
59°C
Matter and Its Properties
77. Chlorine
78. Zinc
MP -102°C
MP 420°C
BP
BP
-34°C
907°C
Chemical Properties
Class Work
79. How do physical properties differ from chemical properties?
80. Where can the most reactive elements be found in the Periodic Table? Where can
the least reactive elements be found?
Homework
For #81-89, label each of these properties as chemical (C) or physical (P). Explain your
choice.
81. Density
82. Tendency to corrode
83. Odor (scent)
84. Boiling/Melting Point
85. Reacts with acid
86. Solubility (dissolves)
87. Flammability
88. Reacts with Oxygen
89. Texture
Answer Key
1) If you were to split one atom of Oxygen in half, you would no longer have Oxygen. All
atoms of Oxygen must have 8 Protons and, in order to be stable, must have 8 Electrons
as well.
2) Protons
3) Electrons
4) Opposites
5) Protons and Neutrons
6) Matter is anything that has mass and takes up space. Every object and substance in the
universe is considered matter.
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7) Something that is not matter would be anything that is not tangible. This includes
feelings, thoughts and emotions. Electricity and magnetic fields are actually matter
(they are the 4th state of matter that we will not discuss in this unit called “plasma”).
8) A “pure substance” is an object that can’t be broken down any further without being
changed into something new.
9) Neutrons
10)Electron Shell
11)
a. Mass = Grams/ kilograms
b. Weight = Pounds
c. Volume = Milliliters / Cubic Centimeters
12)Gravity
13)
a. Less
b. More
c. Less
14)There are 10,000 grams in 10 kg
15)Mass = 10 kg; Weight = 10 lbs
16)Volume = 467.5 cm3
17)To find the volume of an irregular object, you need to fill a graduated cylinder with a
given amount of water, drop the object in, and measure how much the measurement of
the water in the graduated cylinder increased. That amount will be the volume of the
object.
18)22 mL
19)He used common characteristics of the elements to sort them into groups. He then
noticed that there was a pattern in their atomic weights.
20)Mg
21)Carbon
22)Period 1
23)Group 16
24)For a and b, elements with similar characteristics will be those that are located in the
same group:
a. Fluorine – Chlorine, Bromine, Iodine and Astatine
b. Oxygen – Sulfur, Selenium, Tellurium and Polonium
25)The modern Periodic Table of Elements is arranged according to Atomic Number (the
number of protons in one atom)
26)
a. Atomic # = 2
b. Element Symbol = He
c. Atomic Mass = 4
d. Number of Protons = 2
e. Period = 1
f. Group = 18
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g. Number of Electrons in Outer Shell = 2 (There are 2 Protons, therefore there are
only 2 Electrons. Every other element in Group 18 has 8 Outer Electrons)
27)52 Protons
28)Terbium
29)Iodine; Iodine has an atomic number of 53 and Nickel has an atomic number of 28. This
means that Iodine has 53 protons and Nickel has 28.
30)Tungsten
31)Period 5
32)Group 18
33)Same as for #24
a. Potassium – Hydrogen, Lithium, Sodium, Rubidium, Caesium and Francium
b. Krypton – Helium, Neon, Argon, Xenon and Radon
c. Strontium – Beryllium, Magnesium, Calcium, Barium and Radium
d. Gold – Copper and Silver
34)
a. A metal cooking pot will transfer the energy from the heat source (such as a stove
top) to the food in the pot well.
b. Metal power lines will conduct electricity well
c. A metal horseshoe will not bend or break easily if being used for a backyard game.
Metal would also be good for a horseshoe because you can heat the metal up and
mold it into the shape that you need for the horse’s hoof.
d. A metal refrigerator door will allow you to attach magnets.
35) They are placed at the bottom to make the Periodic Table easier to read.
36) Nonmetals are poor conductors of heat and electricity, brittle and dull.
37) Subscript; the subscript tells you how many atoms of a certain element are in a
chemical formula.
38) 1:1
39) 2 Carbon atoms and 2 Hydrogen atoms.
40) Metals are good conductors of heat and electricity, shiny, ductile and malleable.
41)
a. Noble gases
b. Halogens
c. Alkaline earth metals
d. Nonmetals
e. Alkali metals
f. Actinides
g. Lanthanides
42) Compound (or Molecule)
43) An atom is the smallest form of an element. A molecule is the smallest form of a
compound and is made up of more than one atom of one or more elements.
44) The molecule must include 2 Hydrogen atoms and 1 Oxygen atom.
45) CO2
46) 14 Carbon atoms, 18 Hydrogen atoms, 2 Nitrogen atoms and 5 Oxygen atoms
47) D = 0.85 g/cm3
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48) V = 2.5 mL
49) M = 108 g
50) D = 1.28 g/mL
51) D = 1.1 g/cm3; the wood would sink
52) The metal is a sample of Copper (8.86 g/mL)
53) M = 179 g
54) V = 677 mL
55) V = 90.4 mL
56) Solids have definite shape and volume whereas gases do not have definite shape or
volume. The particles of a solid are strongly attracted to each other but the particles of
a gas are not. Because a solid has a definite shape, it is easy to old in your hand. If you
were to try holding a gas in your hand, it would change shape.
57) They differ in two ways: crystalline solids have a regular repeating pattern amorphous solids do not; crystalline solids have a distinct melting point – amorphous
solids do not.
58) Liquids and solids are similar in that they both have a definite volume. They differ in
that liquids do not have a definite shape unlike solids.
59)
a. Definite shape
b. Definite volume
c. Easy to hold
d. Do not move past each other
e. Not a fluid
60)
a. Indefinite shape
b. Definite volume
c. Hard to hold (will roll off your hands!)
d. Particles move past each other
e. Fluid
61)
a. Indefinite shape
b. Indefinite volume
c. Hard to hold
d. Particles move past each other
e. Fluid
62) A fluid is an object that has particles that flow freely.
63) The shape of the solid would not change.
64) The liquid would take the shape of the container in which it was placed.
65) The gas would spread out and fill the entire box.
66) Gas
67) Solid
68) There is no difference between melting and freezing point!
69) Evaporation occurs at the surface of a liquid and boiling occurs below the surface of a
liquid.
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70) When temperature increases, the amount of energy increases. This makes the particles
in an object speed up and vibrate faster.
71) You can tell that water is boiling when water vapor bubbles rise to the surface of the
water and escape. You can tell that water has evaporated when you see that the
amount of water has lessened (such as in a puddle on the road).
72)
a. E
b. E
c. C
d. C
73) Liquid
74) Solid
75) Solid
76) Liquid
77) Gas
78) Solid
79) Physical properties are easily observable without changing the substance. You can
only observe chemical properties by destroying the substance or changing it into
something new (such as setting it on fire).
80) The most reactive are on the left side of the Periodic Table. The least reactive are on
the right side of the Periodic Table.
81) P; When finding the density, you do not destroy the substance, you only measure it.
82) C; Corroding means to break down. If a substance breaks down, the original substance
is destroyed and it has changed into something new.
83) P; By smelling an object, you do not destroy it.
84) P; When a substance changes state, it may look different but it is still the same
substance. For example, when ice melts, it is still water. When liquid water boils, it
remains water.
85) C; If a substance reacts with acid, the original substance is destroyed.
86) P; When you dissolve a substance in another (for example, stirring sugar into water), it
does not just disappear. It keeps its same physical and chemical properties. It is not
destroyed.
87) C; If a flammable substance is lit on fire, it is destroyed. The ash left over is a new
material.
88) C; The word “reacts” is a clue that the original object will be destroyed and it will
become something new.
89) P; You can observe the texture of a substance without destroying it.
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7th Grade PSI
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