2015 8th Grade Science Mid-term Exam

106 Questions | By Rhaveno | Updated: Mar 22, 2022 | Attempts: 163

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1. What forms when one substance dissolves another?

Solution

Solvent

Dissolution

Solute

About This Quiz

2015 8th Grade Science Mid-Term Exam

2. What first name or nickname would you like us to use?

You may optionally provide this to label your report, leaderboard, or certificate.

2. Identify the property of water that allows a water strider insect to walk on the water.

Surface Tension

Polarity

Capillary Action

Specific Heat

3. What is an atom?

The smallest part of an element that is a basic unit of matter

The unit measure of an element

Elements that make up molecules

Neutrons in the nucleus

4. What is a valence electron?

Electrons in the outer cloud of an atom

A negatively charge ion

A positively charge ion

Ionically bonded electrons

5. What is an emulsion?

When one liquid repels another and is neutral.

When a solute dissolves in a solvent.

When a liquid solidifies.

6. Celery test: What property of water does the celery test model?

Capillary Action

Polarity

Surface Tension

Specific Heat

7. Floating Paper Clip:Why does adding liquid detergent to the water change how the paper clip floats?

It breaks the polarity and therefore the surface tension

Liquid detergent is not soluble

It changes the pH

It changes the specific heat

8. Identify the property of water represented in this diagram:

Capillary Action

Polarity

Universal solvency

Surface tension

9. Identify which property of water allows water to move against gravity.

Capillary Action allows water to move against gravity.

Surface tension allows water to move against gravity.

Cohesion allows water to move against gravity.

Universal solvency allows water to move against gravity.

10. Identify: At the surface of a liquid, when water molecules absorb enough energy to change to a gas, the water molecules______________

Evaporate

Condense

Liquify

Solidify

11. What is hydrophobic?

When a molecule repels water

When a molecule is attracted to water

When a molecule is a micelle

When a molecule is ionically bonded

12. A compound is different from an element because a compound is:

Made of two or more elements chemically combined.

The building block of all matter.

A mixture of elements.

A pure substance.

13. A question you seek to answer:

Problem

Qualitative research

Quantitative research

Hypothesis

14. In testing, measurements are:

Constant

Observations

Variable

Data

15. Why is energy needed to dissolve a solute?

Energy is needed to dissolve a solute to break the attractions between particals of solute.

Energy is needed to dissolve a solute to form covalent bonds between particals of solute.

Energy is needed to dissolve a solute to ionically transfer particals of solute.

Energy is needed to dissolve a solute to limit the attractions between particals of solute.

16. What one notices or senses while performing the activity.

Data

Procedure

Observation

Control

17. Steps to follow when testing.

Experiment

Procedure

Control

Theory

18. A suggested solution to a problem question.

Theory

Hypothesis

Conclusion

Data

19. A summary of the relationship between the hypothesis and the test results.

Theory

Hypothesis

Conclusion

Data

20. Water is a universal solvent because:

Water is polar and can dissolve more substances than any other liquid

Solutes are not polar molecules

Water is made up hydrogen and oxygen atoms

Water has a neutral pH

21. Choose the set of terms that identify an atoms' subatomic particles:

Protons, neutrons, electrons

Nucleus, protons, electrons

Nucleus, neutrons, protons

Nucleus, electrons, neutrons

22. Which property is responsible for allowing water (and its dissolved substances) to move through the roots of plants and through the tiny blood vessels in our bodies?

Polarity

Surface tension

Universal solvency

Capillary Action

23. How does an increase in temperature help a solute dissolve?

24. What is adhesion?

Waters ability to stick to other materials

Waters ability to stick to itself

Covalent bonds in water

Capillary Action

25. Choose the terms that best complete the statement: Identify the subatomic particle charges:

Protons (+) positive, Neutrons are neutral, electrons (-) negative

Protons are neutral, neutrons are the nucleus, electrons (-) negative

Protons (-) negative, neutrons (+) positive, electrons (-) negative

Protons (+) positive, neutrons (-) negative, electrons are neutral

26. Choose the statement that best explains: Why do hydrogen atoms usually exist as molecules, H2?

Hydrogen has an atomic number of two and does not need to share

Hydrogen usually combines with other atoms to form covalent bonds

Hydrogen has one proton and is in search of one neutron

27. A general rule in chemistry is that "like dissolves like". This rule means that_______________

28. The process to test the idea.

Theory

Process

Experiment

Control

29. What is demonstrated about water in the 'Follow the String' activity?

Cohesion and adhesion.

Surface tension and adhesion.

Cohesion and capillary action.

Adhesion and capillary action.

30. What is matter?

Matter has mass, takes up space and can exist as a solid, liquid or gas.

Matter is made up of atoms and has weight.

Matter is made up of elements and has weight.

Matter has weight, takes up space and can exist as a solid and liquid only.

31. Choose the response that best explains: Why is water considered a polar molecule?

32. In order to dissolve a substance, solvent particles must be able to __________________

In order to dissolve a substance, solvent particles must be able to covalently and ionically bond with one another.

In order to dissolve a substance, solute particles must be able to attract each other strongly to form a solution.

In order to dissolve a substance, solvent particles must be soluble causing the solvent to dissolve.

33. Dome-de-Dome LabWhich image shows water's relationship to the wax paper in the dome-de-dome lab?

34. Choose the term that best completes the statement: The term ____________ is applied to any substance that cannot be made simpler without changing its chemical make-up.

Element

Atom

Molecule

Substance

35. Pepper and Soap Lab: Why did the pepper move to the sides of the Petri dish when the soap drop entered the water?

Where the soap enters the water the pepper scatters to avoid the soap micelles from surrounding it.

36. The atoms of each element have a unique number of protons in their nuclei.This unique number of protons is called the:

Atomic number

Atomic mass

Subatomic particles

Nucleus

37. Refer to the diagram above: What causes the water molecule to encircle the Sodium Chloride solute?

38. Water as a universal solvent: Identify which group of substances are all soluble:

Ammonia, salt, dishwashing liquid, sugar, vinegar.

Vinegar, salt, sugar, glue, dishwashing liquid.

Vinegar, salt, sugar, hand lotion, dishwashing liquid.

Vinegar,salt, dishwashing liquid, vaseline, sugar.

39. What is wicking?

A material that pulls moisture through by capillary action

Adhesion of water

Cohesion of water

Capillary Action of water

40. How are covalent and ionic bonds different?

Covalent bonds have a neutral electronegativity. Ionic bonds create anions.

Covalent bonds make new elements. Ionic bonds create cations and anions.

41. How does increase in surface area help a solute dissolve more quickly?

42. The electrical attraction between sodium ions (Na+) and chloride ions (Cl-) produces a ___________ arrangement.

The electrical attraction between sodium ions (Na+) and chloride ions (Cl-) produces a crystal arrangement.

The electrical attraction between sodium ions (Na+) and chloride ions (Cl-) produces a hexagonal arrangement.

The electrical attraction between sodium ions (Na+) and chloride ions (Cl-) produces a quadrilateral arrangement.

The electrical attraction between sodium ions (Na+) and chloride ions (Cl-) produces a three cube arrangement.

43. What kind of bonding does this model represent?You and a friend walk past a market that sells apples for 40 cents each and pears for 50 cents each. You have 45 cents and want an apple. Your friend also has 45 cents but wants a pear. You realize that if you give your friend a nickel, she will have 50 cents and can buy a pear. You will have 40 cents left to buy an apple. Transferring the nickel gets both of you what you want. Your actions model what happens between atoms.

Transferring ions is ionic bonding.

Transferring atoms is polyatomic bonding.

The transferring and sharing of atoms is covalent bonding.

Transferring atoms is metallic bonding.

44. Which property of water is capillary action related to?

Adhesion

Cohesion

Surface Tension

Polarity

45. In the water pressure labs: What would you predict about the water coming out of the container if the container holes were made smaller?

46. This image shows two soda bottle streamsLook at this image to answer the question below. Soda bottle stream lab: The soda bottle has vertical cuts for the water to pour out. As the water exits the bottle it forms two individual streams. Identify the property of water that, with each pinch of your fingers, causes the water to combine and flow as one stream of water.

47. Waters high specific heat has a great deal to do with regulating extremes in the environment. How does water's specific heat capacity help the fish in the pond?

48. Look at the map. Apply your knowledge and respond to the questions below. Just as living in a pond, lakes and oceans regulate the temperature ranges of the land masses near them. The average January temperature for Bismarck, North Dakota is -12º C. The average January temperature in Juneau, Alaska is -4º C. 1. Why is Bismarck, colder than Juneau when Juneau is farther north? 2. Which property of water applies?

49.
An electron dot diagram shows the chemical symbol and the_______

An electron dot diagram shows the number of valence electrons in an atom.

An electron dot diagram shows the total number of electrons in an atom.

An electron dot diagram shows the energy levels of the electrons in an atom.

An electron dot diagram shows the bonding electrons in an atom.

50. Water Pressure Lab: Observe these containers:What is the greatest source of the pressure exerted on the water?

Air

Gravity

Water

Surface tension

51. In the pile or water lab: What is the key factor in determining what kind of container of water can hold the most pennies before spilling over?

The size of the container aperture (opening)

The mass of the container

The volume of water the container holds

The weight of the pennies

52. Identify: a substance that is being dissolved is a _________________

Solute

Solution

Solvent

Insoluble

53. In the water pressure lab: What do you predict would happen to the water coming out of the container if the container holes were larger?

If the holes were larger, the volume of water flowing is greater, but slower with less pressure.

If the holes were larger, the volume of water flowing is less, but faster with more pressure.

If the holes were larger, the volume of water flowing is greater, faster and with more pressure.

If the holes were larger, the volume of water flowing is greater, faster and with less pressure.

54. Identify this chain:

This is a hydrocarbon chain of a soap molecule.

This is a food molecule chain.

This is an oxygen, hydrogen and carbon water molecule chain.

This is a soap molecule chain with sodium.

55. When in the shower: What property of water causes it to 'catch' and 'pull' together along the shower wall?

Surface tension of the water

Adhesion of the water

Polarity of the water

Specific heat of the water

56. Identify the water property represented in this diagram: (Too zoom the image, either double tap or use 2 fingers spread to zoom)

Polarity

Specific heat

Universal solvency

Surface tension

57. An explanation of how nature works.

Theory

Conclusion

Law

Hypothesis

58. A substance that dissolves another substance is called a ____________?

Solvent

Solution

Dissolution

Solute

59. This diagram represents H_2. What does the H₂symbol mean?

The H2 symbol represents two atoms of Hydrogen.

The H2 symbol represents a Hydrogen atom.

The H2 symbol represents a water molecule.

The H2 symbol represents an ionic bond.

60. What is an atom's atomic number?

An atom's atomic number is the number of protons in the nucleus of an atom.

An atom's atomic number is the number of the protons and neutrons of the atom.

An atom's atomic number is the number of valence electrons.

An atom's atomic number is the atom's electronegativity.

61. Why do some ionic compounds like silver chloride (AgCl) not dissolve in water while others do?

62. How does stirring or shaking a solution allow more contact between solvent and solute particles?

63. The standard or normal situation for comparison in a test.

Constant

Dependent variable

Variable

Control

64. A statement that describes nature.

Law

Hypothesis

Theory

Conclusion

65. What is an ion?

An electrically charged particle (atom or molecule) whose charge is determined by the loss or gain of electrons.

An electrically charged particle (atom or molecule) whose charge is determined by the sharing of electrons.

An negatively charged particle (atom or molecule).

The electrically charged particles of Ca2+, Mg2+ presence in water.

66. Which is the correct explanation for how table salt, Na⁺Cl^-, ionically bonds?

67. What did Ben Franklin's experiment with nonpolar substances accurately measure?

Ben Franklin accurately measured the thickness of a single-molecule thick layer of olive oil on water.

Ben Franklin accurately measured the pollution in the pond water caused by the olive oil.

Ben Franklin accurately measured the change in surface tension when olive oil was added to the pond.

Ben Franklin accurately measured the area of underwater visibility created by altered surface tension when oil was added to water.

68. Ionic bonding allows atoms to have complete outer shells by:

Ionic bonding is a chemical compound formed by the joining of two or more atoms.

An ionic bond forms a stable compound through the sharing and transfer of valence electrons.

69. A meniscus formed in a graduated cylinder (as in example a. below) is an caused by and an example of what forces acting on the water?

Adhesion and cohesion

Polarity

Surface Tension

Capillary Action

70. What makes valence electrons different from other electrons?

Being in the outer shell, valance electrons can be shared or transferred (removed from or attached to) other atoms.

A valence electron is ionic and can be a cation or an anion.

A valence electron determines the electronegativity of an atom.

71. The noble gases have eight valence electrons. Therefore_____

Noble gases do not react easily with other elements.

Noble gases easily react with other elements.

Nobel gases seek to covalently bond with other elements.

Nobel gases seek to ionically bond with other elements.

72. Elements in the same column of the Periodic Table are called ___________

Elements in the same vertical column of the periodic table are called a family.

Elements in the same vertical column of the periodic table are called a community.

Elements in the same vertical column of the periodic table are called halogens.

Elements in the same vertical column of the periodic table are called a period.

73. What is a micelle?

A cluster of soap molecule beads

A hydrophobic end of a soap molecule

Soap polarity

A hydrophilic end of a soap molecule

74. Identify the property of water that explains why water forms drops.

Cohesion causes surface tension

Polarity

Capillary action

Specific heat

75. Think about the Specific Heat Lab comparing the response to the heat lamp by water and another substance: Why does water retain heat longer than most other substances?

76. This image shows two soda bottle streamsLook at this image to answer the question below. Soda bottle stream lab: The soda bottle has vertical cuts for the water to pour out. Identify the property of water that with each swipe of your hand causes the water to separate and flow as two streams of water.

Cohesion causes each swipe of your hand to separate the single stream into two streams of water.

Adhesion causes each swipe of your hand to separate the single stream into two streams of water.

Polarity causes each swipe of your hand to separate the single stream into two streams of water.

Surface tension causes each swipe of your hand to separate the single stream into two streams of water.

77. In the water pressure lab, of the two containers and three holes: **Which container and which container hole had the least amount of water coming out when the hole was un-taped?**

Capped, top hole

Uncapped, top hole

Uncapped, middle hole

Capped, middle hole

78. What characteristic of water explains why it has many unusual properties?

Water is a polar molecule.

Water is a nonpolar molecule.

Water molecules do not have electrically charges particles.

Water is a universal solvent.

79. A rainy day, think about a car windshield: What causes the raindrops to bead together along the windshield?

Surface tension of the water

Adhesion to the windshield, cohesion of the water molecules

Polarity of the water

Specific heat of the water

80. What is the difference between a compound and a mixture?

A compound is set of element that are blended but not chemically combined. A mixture is made up of emulsifiers.

81. Identify the statement that is correct about the number of protons and electrons in an atom:

The number of protons and the number of electrons in an atom are always equal.

The number of protons is always greater than the number of electrons in an atom.

The number of protons is always less than the number of electrons in an atom.

The number of protons and electrons equals the mass of an atom.

82. What property of water makes it vulnerable to pollution?

Universal solvent

Polarity

Surface Tension

Capillary Action

83. Refer to the diagram above and apply your knowledge. What changes as a water molecule cools?

84. Consider the diagram and apply what you know to respond to this question: Why does water react differently to heat than most substances?

85. In the Periodic Table, when does a period end?

A period ends when the highest energy level has eight electrons.

A period ends when the most active energy level bonds.

A period ends when the valence electrons are traded.

A period ends when the first energy level has two electrons.

86. An isolated factor to test the suggested problem solution.

Data

Independent variable

Variable

Dependent variable

87. Why are Hydrogen covalent bonds non-polar?

88. Ionic Bonding satisfies both atoms because.....

Ionic bonding removes weak electrons from one atom enabling another atom to have strong electronegativity in its outer shell.

Ionic bonding enables one atom to release an electron and vacate its outer shell.

Ionic bonding is the sharing of electrons of atoms that enable the atoms to have complete outer shells.

89. Choose the best response to complete this statement: What is an elements' relationship to an atom?

Elements are composed of atoms that are made of identical particles

Elements are composed of atoms of different kinds of particles

Elements combine to make atoms

Atoms are made up of subatomic particles

90. Which of these is a list of mixtures?

This is a list of mixtures: Air, soil, wood, gasoline, concrete and orange juice.

This is a list of mixtures: Air, soil, saltwater, wood, gasoline, concrete and orange juice.

This is a list of mixtures: Air, soil, water, wood, gasoline, concrete and orange juice.

This is a list of mixtures: Air, soil, wood, gasoline, H2, O2,

91. What do these symbols mean? or

These symbols mean that the atom has either a slight (partial) positive or negative charge.

These symbols mean that the molecule has either a slight (partial) positive or negative charge.

These symbols mean that the atom has a positive or negative electronegativity.

These symbols mean that the atom is polar.

92. What is electronegativity?

How many electrons are in a valence.

The strength of an atoms' electrons.

The electrical charge of a polar molecule.

The exchange of electrons in ionic bonding.

93. What is an energy level?

An area of an atom's cloud in which electrons of the same energy are likely to be found.

A region of an element's cloud in which electrons of the same energy are likely to be found.

The nucleus of an atom in which the same energy level as electrons are found.

The region of an atom in which protons and electrons of the same energy level are likely to be found.

94. A factor that may change in response to the test factor.

Variable

Independent variable

Dependent variable

Data

95. Floating Paper Clip: Why does adding salt to the water change how the paper clip floats?

Salt makes the water more dense, increasing surface tension

Salt makes the water less dense, decreasing surface tension

Salt changes the specific heat of the water, breaking the surface tension

Salt changes the polarity of the water as it dissolves in it

96. Think about Mt. Everest. Complete this statement: As altitude increases, air becomes.......

Less dense, decreasing atmospheric pressure.

More dense, increasing atmospheric pressure.

Less dense, increasing atmospheric pressure.

More dense, decreasing atmospheric pressure.

97. What is a hydrocarbon?

A molecule of hydrogen and carbon, like those that make up waxes and oils

A molecule made up of hydrogen and carbon micelles

A water molecule that bonds with carbon

A soap molecule of hydrogen and carbon

98. The water and air pressure lab:If the lab were done while climbing Mt. Everest, as altitude increases what happens?

99.
Even though it is not a metal, hydrogen is grouped in the family above the alkali metals because_____

Hydrogen is grouped above the alkali metals because it also has one valence electron.

Hydrogen is grouped above the alkali metals because its physical properties resemble those of the alkali metals.

Hydrogen is grouped above the alkali metals because its chemical properties are like those of the alkali metals.

Hydrogen is grouped above the alkali metals because it does not behave like a nonmetal.

100. When a molecular compound (like sugar) dissolves, do the molecules break apart?

When a molecular compound dissolves, the molecules separate and re-bond individually forming Hydrogen bonds.

When a molecular compound dissolves, the molecules move toward the Hydrogen and the individual molecules break apart.

When a molecular compound dissolves, the molecules separate and are distributed evenly over the whole water molecule.

101. What is a chemical bond?

A chemical bond is the force that holds atoms together.

A chemical bond is the nucleus energy level that holds atoms together.

A chemical bond is the exchange of valence electrons.

A chemical bond is the pairing and sharing of electrons.

102. Water Pressure Lab: Observe these containers: Identify the condition the water in the bottle would be under the greatest pressure?

Bottle with the cap off

Cap-on, bottle with the widest opening

Cap-on, bottle with the narrowest opening

None of these

103. How does flour behave when mixed into water?

Flour suspends in water, eventually settling out.

Flour ionically bonds with water because of its crystalline structure.

Flour ionically bonds with water and dissolves

Flour bonds with water because of its powdery structure.

104. A Magic Cup of Water: What two forces act to keep the cardboard in place?

Surface tension and air pressure

Adhesion and cohesion

Surface Tension and adhesion

Adhesion and capillary action

105. In this diagram, the e- represents:

The e- represents the covalent Hydrogen electron bond in this Hydrogen molecule.

The pair of e- represents the double covalent Hydrogen electrons in the Hydrogen molecule.

The pair of e- represents the ionic Hydrogen electrons in this Hydrogen molecule.

The e- represents the single shared Hydrogen electron in this Hydrogen molecule.

106. The number of _______________ determines what element it is and its chemical behavior.

The number of protons determines what element it is and its chemical behavior.

The number of neutrons determines what element it is and its chemical behavior.

The number of protons and neutrons determines what element it is and its chemical behavior.

The number of electrons determines what element it is and its chemical behavior.

Thank you for your feedback!

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What forms when one substance dissolves another?

Identify the property of water that allows a water strider insect to...

What is an atom?

What is a valence electron?

What is an emulsion?

Celery test: What property of water does the celery test model?

Floating Paper Clip:Why does adding liquid detergent to the water...

Identify the property of water represented in this diagram:

Identify which property of water allows water to move against gravity.

Identify: At the surface of a liquid, when water molecules absorb...

What is hydrophobic?

A compound is different from an element because a compound is:

A question you seek to answer:

In testing, measurements are:

Why is energy needed to dissolve a solute?

What one notices or senses while performing the activity.

Steps to follow when testing.

A suggested solution to a problem question.

A summary of the relationship between the hypothesis and the test...

Water is a universal solvent because:

Choose the set of terms that identify an atoms' subatomic...

Which property is responsible for allowing water (and its dissolved...

How does an increase in temperature help a solute dissolve?

What is adhesion?

Choose the terms that best complete the statement: Identify the...

Choose the statement that best explains: Why do hydrogen atoms usually...

A general rule in chemistry is that "like dissolves like"....

The process to test the idea.

What is demonstrated about water in the 'Follow the String'...

What is matter?

Choose the response that best explains: Why is water considered a...

In order to dissolve a substance, solvent particles must be able to...

Dome-de-Dome LabWhich image shows water's relationship to the wax...

Choose the term that best completes the statement: The term...

Pepper and Soap Lab: Why did the pepper move to the sides of the Petri...

The atoms of each element have a unique number of protons in their...

Refer to the diagram above: What causes the water molecule to encircle...

Water as a universal solvent: Identify which group of substances...

What is wicking?

How are covalent and ionic bonds different?

How does increase in surface area help a solute dissolve more quickly?

The electrical attraction between sodium ions (Na+) and chloride ions...

What kind of bonding does this model represent?You and a friend walk...

Which property of water is capillary action related to?

In the water pressure labs: What would you predict about the water...

This image shows two soda bottle streamsLook at this image to answer...

Waters high specific heat has a great deal to do with regulating...

Look at the map. Apply your knowledge and...

An electron dot diagram shows the chemical symbol and...

Water Pressure Lab: Observe these containers:What is the greatest...

In the pile or water lab: What is the key factor in determining what...

Identify: a substance that is being dissolved is a _________________

In the water pressure lab: What do you predict would happen to the...

Identify this chain:

When in the shower: What property of water causes it to...

Identify the water property represented in this diagram: (Too zoom the...

An explanation of how nature works.

A substance that dissolves another substance is called a ____________?

This diagram represents H2. What does...

What is an atom's atomic number?

Why do some ionic compounds like silver chloride (AgCl)...

How does stirring or shaking a solution allow more contact between...

The standard or normal situation for comparison in a test.

A statement that describes nature.

What is an ion?

Which is the correct explanation for how table salt, Na+Cl-,...

What did Ben Franklin's experiment with nonpolar substances...

Ionic bonding allows atoms to have complete outer shells by:

A meniscus formed in a graduated cylinder (as in example a. below) is...

What makes valence electrons different from other electrons?

The noble gases have eight valence electrons. Therefore_____

Elements in the same column of the Periodic Table are called...

What is a micelle?

Identify the property of water that explains why water forms drops.

Think about the Specific Heat Lab comparing the response to the heat...

This image shows two soda bottle streamsLook at this image to answer...

In the water pressure lab, of the two containers and three holes:...

What characteristic of water explains why it has many unusual...

A rainy day, think about a car windshield: What causes the raindrops...

What is the difference between a compound and a mixture?

Identify the statement that is correct about the number of protons and...

What property of water makes it vulnerable to pollution?

...

Consider the diagram and apply what you know to respond to this...

In the Periodic Table, when does a period end?

An isolated factor to test the suggested problem solution.

Why are Hydrogen covalent bonds non-polar?

Ionic Bonding satisfies both atoms because.....

Choose the best response to complete this statement: What is an...

Which of these is a list of mixtures?

What do these symbols mean? or

What is electronegativity?

What is an energy level?

A factor that may change in response to the test factor.

Floating Paper Clip: Why does adding salt to the water change how the...

Think about Mt. Everest. Complete this statement: As altitude...

What is a hydrocarbon?

The water and air pressure lab:If the lab were done...

Even though it is not a metal, hydrogen is grouped in the...

When a molecular compound (like sugar) dissolves, do the...

What is a chemical bond?

Water Pressure Lab: Observe these containers: Identify the condition...

How does flour behave when mixed into water?

A Magic Cup of Water: What two forces act to keep the cardboard in...

In this diagram, the e- represents:

The number of _______________ determines what element it is and its...

2015 8th Grade Science Mid-term Exam

1. What forms when one substance dissolves another?

2.

What first name or nickname would you like us to use?

2. Identify the property of water that allows a water strider insect to walk on the water.

3. What is an atom?

4. What is a valence electron?

5. What is an emulsion?

6. Celery test: What property of water does the celery test model?

7. Floating Paper Clip:Why does adding liquid detergent to the water change how the paper clip floats?

8. Identify the property of water represented in this diagram:

9. Identify which property of water allows water to move against gravity.

10. Identify: At the surface of a liquid, when water molecules absorb enough energy to change to a gas, the water molecules______________

11. What is hydrophobic?

12. A compound is different from an element because a compound is:

13. A question you seek to answer:

14. In testing, measurements are:

15. Why is energy needed to dissolve a solute?

16. What one notices or senses while performing the activity.

17. Steps to follow when testing.

18. A suggested solution to a problem question.

19. A summary of the relationship between the hypothesis and the test results.

20. Water is a universal solvent because:

21. Choose the set of terms that identify an atoms' subatomic particles:

22. Which property is responsible for allowing water (and its dissolved substances) to move through the roots of plants and through the tiny blood vessels in our bodies?

23. How does an increase in temperature help a solute dissolve?

24. What is adhesion?

25. Choose the terms that best complete the statement: Identify the subatomic particle charges:

26. Choose the statement that best explains: Why do hydrogen atoms usually exist as molecules, H2?

27. A general rule in chemistry is that "like dissolves like". This rule means that_______________

28. The process to test the idea.

29. What is demonstrated about water in the 'Follow the String' activity?

30. What is matter?

31. Choose the response that best explains: Why is water considered a polar molecule?

32. In order to dissolve a substance, solvent particles must be able to __________________

33. Dome-de-Dome LabWhich image shows water's relationship to the wax paper in the dome-de-dome lab?

34. Choose the term that best completes the statement: The term ____________ is applied to any substance that cannot be made simpler without changing its chemical make-up.

35. Pepper and Soap Lab: Why did the pepper move to the sides of the Petri dish when the soap drop entered the water?

36. The atoms of each element have a unique number of protons in their nuclei.This unique number of protons is called the:

37. Refer to the diagram above: What causes the water molecule to encircle the Sodium Chloride solute?

38. Water as a universal solvent: Identify which group of substances are all soluble:

39. What is wicking?

40. How are covalent and ionic bonds different?

41. How does increase in surface area help a solute dissolve more quickly?

42. The electrical attraction between sodium ions (Na+) and chloride ions (Cl-) produces a ___________ arrangement.

44. Which property of water is capillary action related to?

45. In the water pressure labs: What would you predict about the water coming out of the container if the container holes were made smaller?

47. Waters high specific heat has a great deal to do with regulating extremes in the environment. How does water's specific heat capacity help the fish in the pond?

49. An electron dot diagram shows the chemical symbol and the_______

50. Water Pressure Lab: Observe these containers:What is the greatest source of the pressure exerted on the water?

51. In the pile or water lab: What is the key factor in determining what kind of container of water can hold the most pennies before spilling over?

52. Identify: a substance that is being dissolved is a _________________

53. In the water pressure lab: What do you predict would happen to the water coming out of the container if the container holes were larger?

54. Identify this chain:

55. When in the shower: What property of water causes it to 'catch' and 'pull' together along the shower wall?

56. Identify the water property represented in this diagram: (Too zoom the image, either double tap or use 2 fingers spread to zoom)

57. An explanation of how nature works.

58. A substance that dissolves another substance is called a ____________?

59. This diagram represents H2. What does the H2 symbol mean?

60. What is an atom's atomic number?

61. Why do some ionic compounds like silver chloride (AgCl) not dissolve in water while others do?

62. How does stirring or shaking a solution allow more contact between solvent and solute particles?

63. The standard or normal situation for comparison in a test.

64. A statement that describes nature.

65. What is an ion?

66. Which is the correct explanation for how table salt, Na+Cl-, ionically bonds?

67. What did Ben Franklin's experiment with nonpolar substances accurately measure?

68. Ionic bonding allows atoms to have complete outer shells by:

69. A meniscus formed in a graduated cylinder (as in example a. below) is an caused by and an example of what forces acting on the water?

70. What makes valence electrons different from other electrons?

71. The noble gases have eight valence electrons. Therefore_____

72. Elements in the same column of the Periodic Table are called ___________

73. What is a micelle?

74. Identify the property of water that explains why water forms drops.

75. Think about the Specific Heat Lab comparing the response to the heat lamp by water and another substance: Why does water retain heat longer than most other substances?

77. In the water pressure lab, of the two containers and three holes: Which container and which container hole had the least amount of water coming out when the hole was un-taped?

78. What characteristic of water explains why it has many unusual properties?

79. A rainy day, think about a car windshield: What causes the raindrops to bead together along the windshield?

80. What is the difference between a compound and a mixture?

81. Identify the statement that is correct about the number of protons and electrons in an atom:

49.
An electron dot diagram shows the chemical symbol and the_______

59. This diagram represents H_2. What does the H₂symbol mean?

66. Which is the correct explanation for how table salt, Na⁺Cl^-, ionically bonds?

77. In the water pressure lab, of the two containers and three holes: **Which container and which container hole had the least amount of water coming out when the hole was un-taped?**

91. What do these symbols mean? or

99.
Even though it is not a metal, hydrogen is grouped in the family above the alkali metals because_____