Questions and Answers of Integrated Science

Stars that are faint, very dense, white hot, and close to the end of their lifetime area. red giant stars.b. novas.c. white dwarf stars.d. Cepheid variable stars.
Whether the universe will continue to expand or will collapse back into another big bang seems to depend on what property of the universe?a. the density of matter in the universeb. the age of
Dark energy calculations and the age of cooling white dwarfs indicate that the universe is about how old?a. 6,000 yearsb. 4.5 billion yearsc. 13.7 billion yearsd. 100,000 billion years
The greater the distance to a galaxy, the greater a redshift in its spectral lines. This is known asa. Doppler’s law.c. Hubble’s law.b. Cepheid’s law.d. Kepler’s law.
The basic unit of the universe is aa. star.c. galactic cluster.b. solar system. d . galaxy.
If the core remaining after a supernova has a mass between 1.5 and 3 solar masses, it collapses to form aa. white dwarf.c. red giant.b. neutron star.d. black hole.
All the elements that are more massive than the element iron were formed in aa. nova.c. supernova.b. white dwarf.d. black hole.
The basic property of a main sequence star that determines most of its other properties, including its location on the H-R diagram, isa. brightness.c. temperature.b. color.d. mass.
A bright blue star on the main sequence is probablya. very massive.b. less massive.c. between the more massive and the less massive.d. None of the above is correct.
Which of the following stars would have the longer life spans?a. the less massiveb. between the more massive and the less massivec. the more massived. All have the same life span.
Stars twinkle and planets do not twinkle becausea. planets shine by reflected light, and stars produce their own light.b. all stars are pulsing light sources.c. stars appear as point sources of
What are the similarities and diff erences between a nuclear fi ssion power plant and a nuclear fusion power plant?
Write a letter to your congressional representative describing why used nuclear fuel rods should be reprocessed rather than buried as nuclear waste.
Explain how the fi ssion of heavy elements and the fusion of light elements both release energy.
Suppose you believe the threshold model of radiation exposure is correct. Describe a conversation between yourself and another person who feels strongly that the linear model of radiation exposure is
Make up a feasible explanation for why some isotopes have half-lives of seconds, yet other kinds of isotopes have half-lives in the billions of years.
Analyze the diff erent types of radioactive decay to explain how each is a hazard to living organisms.
What are the signifi cant diff erences between a radioactive isotope and an isotope that is not radioactive?
Compare and contrast nuclear fi ssion and nuclear fusion.
What is a mass defect? How is it related to the binding energy of a nucleus? How can both be calculated?
Why is there controversy about the eff ects of long-term, low levels of radiation exposure?
What is meant by background radiation? What is the normal radiation dose for the average person from background radiation?
Would you expect an isotope with a long half-life to be more, the same, or less radioactive than an isotope with a short halflife?Explain.
What is half-life? Give an example of the half-life of an isotope, describing the amount remaining and the time elapsed aft er fi ve half-life periods.
How are positively charged protons able to stay together in a nucleus since like charges repel?
Describe three kinds of radiation emitted by radioactive materials. Describe what eventually happens to each kind of radiation aft er it is emitted.
What is radioactive decay? Describe how the radioactive decay rate can be changed if this is possible.
How is a radioactive material diff erent from a material that is not radioactive?
Used fuel rods from a nuclear reactor contain abouta. 96% usable uranium and plutonium.b. 33% usable uranium and plutonium.c. 4% usable uranium and plutonium.d. 0% usable uranium and plutonium.
A measure of radiation received that considers the biological effect resulting from the radiation is (the)a. curie.b. rad.c. rem.d. Any of the above is correct.
A measure of radioactivity at the source is (the)a. curie .b. rad.c. rem.d. Any of the above is correct.
Isotope A has a half-life of seconds, and isotope B has a halflife of millions of years. Which isotope is more radioactive?a. It depends on the sample size.b. isotope Ac. isotope Bd. Unknown from the
The rate of radioactive decay can be increased by increasing thea. temperature.b. pressure.c. size of the sample.d. None of the above is correct.
An atom of an isotope with a large neutron-to-proton ratio will probably emit a (an)a. alpha particle.b. beta particle.c. gamma ray.d. None of the above is correct.
An atom of an isotope with an atomic number greater than 83 will probably emit a (an)a. alpha particle.b. beta particle.c. gamma ray.d. None of the above is correct.
The most penetrating of the three common types of nuclear radiation is thea. alpha particle.b. beta particle.c. gamma ray.d. All have equal penetrating ability.
A sheet of paper will stop a (an)a. alpha particle.b. beta particle.c. gamma ray.d. None of the above is correct.
An atom of radon-222 loses an alpha particle to become a more stable atom ofa. radium.b. bismuth.c. polonium.d. radon.
The ejection of an alpha particle from a nucleus results ina. an increase in the atomic number by one.b. an increase in the atomic mass by four.c. a decrease in the atomic number by two.d. None of
A high-speed electron ejected from a nucleus during radioactive decay is called a (an)a. alpha particle.b. beta particle.c. gamma ray.d. None of the above is correct.
Describe at least four diff erent examples of how you could make hard water soft .
Describe how you would teach someone why the pH of an acid is a low number (less than 7), while the pH of a base is a larger number (greater than 7).
What are the signifi cant similarities and diff erences between an acid, a base, and a salt?
Th ere are at least three ways to change the boiling point of water, so describe how you know for sure that 100 ° C (212 ° F) is the boiling point.
What is the same and what is diff erent between a salt that will dissolve in water and one that is insoluble?
Analyze the basic reason that water is a universal solvent, becomes less dense when it freezes, has a high heat of fusion, has a high specifi c heat, and has a high heat of vaporization.
What ion is responsible for (a) acidic properties? (b) for basic properties?
What feature of a soap molecule gives it cleaning ability?
What is a hydrogen bond? Explain how a hydrogen bond forms.
According to the defi nition of an acid and the defi nition of a base, would the pH increase, decrease, or remain the same when NaCl is added to pure water? Explain.
What is hard water? How is it soft ened?
Explain why water has a greater density at 4 ° C than at 0 ° C.
A deep lake in Minnesota is covered with ice. What is the water temperature at the bottom of the lake? Explain your reasoning.
Explain why adding salt to water increases the boiling point.
Explain why some ionic compounds are soluble while others are insoluble in water.
How is a solution diff erent from other mixtures?
The heat of fusion, specific heat, and heat of vaporization of water are high compared to similar substances such as hydrogen sulfide, H2S, becausea. ionic bonds form in water molecules.b. hydrogen
The solubility of most ionic salts in watera. increases with temperature increase.b. decreases with temperature increase.c. depends on the amount of salt.d. increases with stirring.
Hard water is a solution ofa. Na+ and Cl ions.b. Na+ and K+ ions.c. Ca2+ and Mg2+ ions.d. Ba2+ and Cl ions.
As the temperature of water decreases, the solubility of carbon dioxide gas in the watera. increases.b. decreases.c. remains the same.d. increases or decreases, depending on the specific temperature.
This means thata. substance A has more basic properties than substance B.b. substance B has more acidic properties than substance A.c. substance A is ten times more acidic than substance B.d.
Substance A has a pH of 2 and substance B has a pH of
Which of the following would have a pH of more than 7?a. a solution of ammoniab. a solution of sodium chloridec. pure waterd. carbonic acid
Which of the following would have a pH of less than 7?a. a solution of ammoniab. a solution of sodium chloridec. pure waterd. carbonic acid
The ice that forms in freezing seawater isa. pure water.b. the same salinity as liquid seawater.c. more salty than liquid seawater.d. more dense than liquid seawater.
A solid salt is insoluble in water, so the strongest force must be thea. ion-water molecule force.b. ion-ion force.c. force of hydration.d. polar molecule force.
Water has the greatest density at what temperature?a. 100 ° Cb. 20 ° Cc. 4 ° Cd. 0 ° C
Atmospheric air is a homogeneous mixture of gases that is mostly nitrogen gas. The nitrogen is therefore (the)a. solvent.b. solution.c. solute.d. None of the above is correct.
Which of the following is not a solution?a. seawaterb. carbonated waterc. sandd. brass
Summarize for another person the steps needed for successfully writing a balanced chemical equation.
Provide several examples of each of the four basic categories of chemical reactions and describe how each illustrates a clear representation of the category.
What are the advantages and disadvantages to writing a chemical equation with chemical symbols and formulas rather than just words?
Make up an explanation for why ionic compounds are formed when a metal from the left side of the periodic table reacts with a nonmetal from the right side, but covalent bonds are formed between
Analyze how you would know for sure that a pure substance you have is an element and not a compound.
Analyze how you would know for sure that a pure substance you have is a compound and not an element.
What are the signifi cant similarities and diff erences between a physical change and a chemical change?
Predict the products for the following reactions: (a) the combustion of ethyl alcohol (C 2 H 5 OH), and (b) the rusting of aluminum (Al).
What must occur in order for an ion exchange reaction to take place? What is the result if this does not happen?
How is the activity series for metals used to predict if a replacement reaction will occur or not?
Describe in your own words how a chemical equation is balanced.
What is the law of conservation of mass? How do you know if a chemical equation is in accord with this law?
What is the basic diff erence between a single bond and a double bond?
Write the formula for magnesium hydroxide. Explain what the parentheses mean.
What is a polyatomic ion? Give the names and formulas for several common polyatomic ions.
What is the octet rule and why is it important?
What is the diff erence between an ionic and covalent bond?What do atoms forming the two bond types have in common?
Describe how the following are alike and how they are diff erent: (a) a sodium atom and a sodium ion, and (b) a sodium ion and a neon atom.
What is the diff erence between a chemical change and a physical change? Give three examples of each.
A balanced chemical equation hasa. the same number of molecules on both sides of the equation.b. the same kinds of molecules on both sides of the equation.c. the same number of each kind of atom on
Of the elements listed below, the one with the greatest chemical activity isa. aluminum.b. zinc.c. iron.d. mercury.
When carbon burns with an insufficient supply of oxygen, carbon monoxide is formed according to the following equation: 2 C O 2 → 2 CO. What category of chemical reaction is this?a. combinationb.
Since wood is composed of carbohydrates, you should expect what gases to exhaust from a fireplace when complete combustion takes place?a. carbon dioxide, carbon monoxide, and pollutantsb. carbon
A chemical equation is balanced by changing (the)a. subscripts.b. superscripts.c. coefficients.d. any of the above as necessary to achieve a balance.
Dihydrogen monoxide is a compound with the common name ofa. laughing gas.c. smog.b. water.d. rocket fuel.
An inorganic compound made of only two different elements has a name that always ends with the suffixa. -ite.c. -ide.b. -ate.d. -ous.
Which combination of elements forms crystalline solids that will dissolve in water, producing a solution of ions that conduct an electric current?a. metal and metalb. metal and nonmetalc. nonmetal
Which type of chemical bond is formed between two atoms by the sharing of electrons?a. ionicb. covalentc. metallicd. None of the above is correct.
The electrons that participate in chemical bonding are (the)a. valence electrons.b. electrons in fully occupied orbitals.c. stable inner electrons.d. All of the above are correct.
A pure substance that cannot be decomposed into anything simpler by chemical or physical means is called a (an)a. element.b. compound.c. mixture.d. isotope.
Which of the following represents a chemical change?a. heating a sample of ice until it meltsb. tearing a sheet of paper into tiny piecesc. burning a sheet of paperd. All of the above are correct.

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