QUESTION 1Which of the following represents the most stable

QUESTION 1Which of the following represents the most stable arrangement of electrons?a.atoms with completely filled valence shellsb.elements that are positioned on the far right column of the periodic table of elementsc.inert gases such as helium, neon and argond.atoms with a total of 2, 10, 18 or 36 electronse.any or all of these answers are correct2 points QUESTION 2Freezing and boiling are examples ofa.processes that cause physical changes.b.oxidation/reduction reactions.c.polymerization.d.temperature changes that form ionic bonds.e.processes that cause chemical changes.2 points QUESTION 3The electrons at the outer level of the atom are calleda.outer field electrons.b.the atomic number.c.valence electrons.d.van de Waals electrons.e.ionic electrons.2 points QUESTION 4Which state of matter maintains a constant volume but not a fixed shape?a.gasb.plasmac.liquidd.crystale.solid2 points QUESTION 5Which kind of strength describes a material’s ability to withstand twisting?a.compressiveb.shearc.bruted.tensilee.flexible2 points QUESTION 6Doping is a process that addsa.phosphorus ions to the crystalline structure of silicon.b.aluminum ions to the crystalline structure of silicon.c.any minor impurity to an element or compound.d.a positive or negative charge to the lattice of a crystal.e.all of these2 points QUESTION 7Which of the following is true about radioactive decay?a.Once a nucleus begins to decay it is destroyed.b.A helium proton was the first particle identified as a product of radioactive decay.c.Gamma decay depends on chemical reactions.d.Alpha decay results in one less neutron and one more proton.e.After beta decay, the number of protons in a nucleus is unchanged.2 points QUESTION 8How do two isotopes of the same element differ?a.Their nuclei have different number of protons.b.Their electrons have different orbits.c.They have different electrical charges.d.Their neutrons differ in number.e.They have a different atomic number.2 points QUESTION 9The difference between nuclear fusion and nuclear fission is thata.Energy is released from fusion, but not from fission.b.Energy is released from fission, but not from fusion.c.Fusion splits apart a nucleus; fission combines two nuclei into one.d.Fusion combines two nuclei into one, fission splits apart a nucleus.e.Only fission is involved in hydrogen bomb explosions; both fusion and fission are required for atomic bomb explosions.2 points QUESTION 10The energy source of stars is primarily associated witha.the reactions of atoms in the star corona.b.the reactions of nuclei in the star core.c.the reactions of atoms in the outer regions of the star.d.burning of elements until they become radioactive.e.burning of elements heavier than lead.2 points QUESTION 11At this moment, the Sun is producing energy by burninga.plutonium.b.anthracite.c.hydrogen.d.helium.e.iron.2 points QUESTION 12Approximately how long does it take the energy of the Sun to be transferred from the stellar core to the photosphere?a.one light-yearb.many thousands of yearsc.24 hoursd.one monthe.eight minutes2 points QUESTION 13The Big Bang theory and the theory of the steady state universe differa.because only the Big Bang theory states that the universe is expanding.b.because only the steady state theory states that the universe is expanding.c.in that only the steady state theory lacks a specific beginning for the universe.d.in that only the steady state universe incorporates an idea about the missing dark matter.e.only in name.2 points QUESTION 14The discovery of a cosmic microwave backgrounda.supported the idea of a steady state universe.b.showed that the universe has a constant heat source.c.proved that matter in the universe is grouped in superclusters.d.gave support to the Big Bang theory.e.indicated that supernovas produced all known elements.2 points QUESTION 15According to the nebular hypothesis, the solar system began asa.a rapidly rotating sun.b.a cloud of dust and gas.c.a cloud containing approximately equal amounts of all naturally occurring elements.d.two comets that collided with a tremendous impact.e.a vast area of totally empty space.2 points QUESTION 16The Earth’s layered composition is a consequence ofa.the great bombardment.b.differentiation of materials.c.isolation.d.condensation currents.e.plate tectonics.2 points QUESTION 17Scientists study meteoritesa.because they contain the material from which the solar system was made.b.to find out more about how and when the Earth was created.c.to find out more about other parts of the solar system.d.for all the above reasons.e.Scientists cannot study meteorites because they burn up when they hit the Earth’s atmosphere.2 points QUESTION 18Which of the following was used as evidence for plate tectonics?a.topographic profiles of the ocean floorsb.maps on rock magnetismc.data classifying rocks by aged.sea floor spreadinge.all of these are correct2 points QUESTION 19Which of the following describes earthquakes?a.Earthquakes are an abrupt release of energy.b.Prediction of earthquakes is an established science, which gives global citizens a chance to evacuate ahead of time.c.Earthquakes have never occurred in the middle of the USA.d.No earthquake has been measured higher than 7 on the Richter scale.e.All earthquakes happen within one kilometer of the Earth’s surface.2 points QUESTION 20Divergent plate boundaries are associated witha.seafloor spreading.b.formation of new crust.c.volcanic action.d.shallow, low-energy earthquakes.e.all of these are correct2 points QUESTION 21Every atom in nature attempts to reach a state of lowestenergy. True False2 points QUESTION 22When atoms bond to form molecules the chemical potentialenergy is higher than it was before the bonding. True False2 points QUESTION 23Strength is the ability of a solid to resist changes in shape. True False2 points QUESTION 24A semiconductor is neither a good conductor nor a goodinsulator. True False2 points QUESTION 25The electric path that begins at a power plant and ends at yourdesk lamp contains only materials that are good conductors ofelectricity. True False2 points QUESTION 26The energies available in the nucleus are much greater than theenergies available among electrons. True False2 points QUESTION 27Reactions that occur in the nucleus of an atom are independentfrom chemistry controlled by the electrons True False2 points QUESTION 28The name of an element depends on the number of protons inthe nucleus of the atom. True False2 points QUESTION 29Some stars will burn forever True False2 points QUESTION 30The absolute magnitude of a star is the brightness as seenfrom Earth, depending on the star’s distance from Earth. True False2 points QUESTION 31A main sequence star in the H-R diagram is in the hydrogen burning stage of its existence. True False2 points QUESTION 32Most galaxies are spiral galaxies. True False2 points QUESTION 33The more distant a galaxy is from Earth, the slower it movesaway from Earth. True False2 points QUESTION 34Elements with more than three protons in their nucleus wereformed in stars, not during the big bang. True False2 points QUESTION 35The mantle is the one of two layers of the solid Earth with whichhuman beings have had direct contact. True False2 points QUESTION 36NASA scientists are collaborating with the Center for DiseaseControl on a mission to collect and bring back surface samples from Mars. True False2 points QUESTION 37Mountains on the Earth are continuously being formed. True False2 points QUESTION 38Energy from earthquakes is transmitted as light waves. True False2 points QUESTION 39Evidence for Earth’s magnetic reversals has been found in the EastAfrican Rift Zone. True False2 points QUESTION 40The Appalachian Mountains are among the youngest on Earth. True False2 points QUESTION 41The subsurface molten rock at the base of a volcano is called 2 points QUESTION 42An oceanic wave generated by an offshore earthquake is a/an 2 points QUESTION 43The hypothesis is the current scientific explanation of how the solar system formed 2 points QUESTION 44A/an is a star that rotates rapidly and emits regular bursts of electromagnetic energy.2 points QUESTION 45The brightness of a star as it appears from earth is called its magnitude.2 points QUESTION 46Unlike the fission bomb, the hydrogen bomb relies on nuclear 2 points QUESTION 47The ability to withstand pulling apart is referred to as strength.2 points QUESTION 48The addition of a minor impurity to an element or compound is called 2 points QUESTION 49The second electron shell out from the nucleus of the atom holds a maximum of electrons.2 points QUESTION 50Two or more metals can be formed to from a/an 2 points Click Save and Submit to save and submit. 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