Q&A Hero

Q: Why can't we see atoms? A) We see with light energy and the wavelength is larger than the object and so it is not reflected. B) Atoms are invisible. C) We cannot see things that are microscopic. D) We see with light energy but the atoms absorb all the light and therefore there are no reflections. E) Atoms do not interact with light energy and therefore we are unable to observe them with light.

Q: Which of the following could be represented by a physical model? A) a cell B) an atom C) rationality D) ecosystem E) both A and B

Q: Which of the following couldNOT be represented by a conceptual model? A) the energy of a nucleus B) the floor plan of a house C) the weather D) the behavior of schoolchildren E) both A and B

Q: What is the main difference between a conceptual model and a physical model? A) A physical model represents shape and form while a conceptual model describes behavior. B) A conceptual model represents shape and form while a physical model describes behavior. C) Only physical models can be used to represent the real world. D) Only conceptual models can be used to depict concepts. E) Physical models and conceptual models can be used to describe the same things.

Q: Which of the following best describes a conceptual model of an atom? A) a model that illustrates the tendency of an atom to undergo chemical bonding B) a model that illustrates the physical structure of the atom C) a model that represents the shape of the nucleus D) a description of the location of the neutrons and protons in an atom E) none of the above

Q: If an atom were the size of a baseball, its nucleus would be about the size of a(n) A) walnut. B) raisin. C) flea. D) atom.

Q: What do the components of a conceptual model have in common? A) All components interact with each other. B) All components are mutually independent of each other. C) The components have nothing in common. This is what differentiates a conceptual model from a physical model. D) Each component must correlate with a corresponding component of a physical model.

Q: Would you use a physical model or a conceptual model to describe the following: the brain; the mind; the solar system; the beginning of the universe? A) conceptual; physical; conceptual physical B) conceptual; conceptual; conceptual; conceptual C) physical; conceptual; physical; conceptual D) physical; physical; physical; physical

Q: Would you use a physical model or a conceptual model to describe the following: a gold coin, dollar bill, car engine, air pollution, virus, spread of sexually transmitted disease? A) conceptual modelgold coin, car engine, virus; physical modelair pollution, spread of sexually transmitted disease, dollar bill B) physical modelgold coin, car engine, virus; conceptual modelair pollution, spread of sexually transmitted disease; dollar bill, which could represent wealth, may well be described by either model. C) You could adequately describe all of the topics by either model. The choice depends only on the characteristics requiring description. D) physical modelgold coin, dollar bill, car engine; conceptual modelvirus, air pollution, spread of sexually transmitted disease

Q: Which of these does not describe a metal at room temperature? A) gas B) solid C) liquid D) shiny E) bendable

Q: Which of these is not a metal? A) selenium (atomic no. = 34) B) gallium (atomic no. = 31) C) lithium (atomic no. = 3) D) potassium (atomic no. = 19) E) vanadium (atomic no. = 23)

Q: Which of these properties describes a metal? A) conducts heat very well B) brittle C) fragile D) transparent E) doesn't conduct electricity very well

Q: Which of the following describes a nonmetal? A) poor conductor of electricity B) shiny C) malleable D) ductile E) good conductor of heat

Q: Which of the following is not a nonmetal? A) titanium (atomic no. = 22) B) sulfur (atomic no. = 16) C) selenium (atomic no. = 34) D) xenon (atomic no. = 54) E) helium (atomic no. = 2)

Q: What are metalloids? A) elements that have some properties like metals and some like nonmetals B) elements that are smaller than metals C) elements found in asteroids D) elements that are larger than nonmetals E) elements that have properties different than either the metals or the nonmetals

Q: Which of the following is a metalloid? A) antimony (atomic no. = 51) B) zinc (atomic no. = 30) C) iodine (atomic no. = 53) D) uranium (atomic no. = 92) E) sulfur (atomic no. = 16)

Q: Which atom is largest? A) Rb B) K C) Na D) Li E) H

Q: Which atom is smallest? A) Be B) Mg C) Ca D) Sr E) All are the same size.

Q: Which of the following elements are in the same period as magnesium (Mg)? A) Cl B) Ca C) Mn D) Sr E) none of the above

Q: Which of the following elements are in the same group as silicon (Si)? A) C B) P C) As D) B E) none of the above

Q: Elements that are in the same ________ have a tendency to have very similar chemical properties due to periodic trends. A) group B) period C) textbook D) compound E) row

Q: Which of the following is not the name of a chemical family? A) heavy metals B) transition metals C) alkali metals D) alkaline-earth metals E) noble gases

Q: Which chemical family is composed almost entirely of man-made elements? A) the actinides B) the lanthanides C) the halogens D) all of the above E) none of the above

Q: Which element would have chemical properties the most similar to chlorine (Cl)? A) Br B) O C) Ar D) S E) Na

Q: The repeating trends that take place when examining the elements are called A) periodic. B) the family cycle. C) the metal shift. D) a group conscience. E) none of the above

Q: Which of the following elements is a gas at room temperature? A) argon (Ar) B) lead (Pb) C) cesium (Cs) D) indium (In) E) lithium (Li)

Q: Which of the following elements is a halogen? A) argon (Ar) B) lead (Pb) C) chlorine (Cl) D) indium (In) E) lithium (Li)

Q: Which of the following elements is an alkali metal? A) argon (Ar) B) lead (Pb) C) cerium (Cr) D) indium (In) E) lithium (Li)

Q: Which of the following elements is a transition metal? A) xenon (Xe) B) lead (Pb) C) chlorine (Cl) D) silver (Ag) E) lithium (Li)

Q: Which of the following elements is in the fourth period? A) chromium (Cr) B) hydrogen (H) C) beryllium(Be) D) carbon (C) E) zirconium (Zr)

Q: Which of the following elements will most likely be shiny and malleable? A) rhodium (Rh) B) hydrogen (H) C) helenium (Se) D) iodine (I) E) silicon (Si)

Q: Which of the following physical properties would you expect for krypton (Kr)? A) a gas at room temperature B) hard C) brittle D) shiny E) conducts electricity

Q: What happens to the properties of elements across any period of the periodic table? A) The elements tend to become more metallic in nature since they are increasing in atomic number. B) The elements get much larger in size because of the addition of more protons and electrons. C) The properties of the elements gradually change across any period of the periodic table. D) All of the above are true.

Q: The oldest known elements in the periodic table are the ones with A) the lowest atomic numbers. B) the highest atomic numbers. C) odd looking atomic symbols. D) atomic symbols that match their modern names.

Q: Germanium, Ge (number 32), computer chips operate faster than silicon, Si (number 14), computer chips. So how might a gallium, Ga (number 31), chip compare with a germanium chip? A) A gallium chip would be even faster because the gallium is more metallic. B) A gallium chip would be slower because its electrons are more loosely held. C) Gallium is located just below aluminum, which is widely known to be an electrical insulator. D) Gallium is more nonmetallic and so it does not conduct electrons very well.

Q: Helium, He, is a nonmetallic gas and the second element in the periodic table. Rather than being placed adjacent to hydrogen, H, however, helium is placed on the far right of the table because A) hydrogen and helium repel one another. B) the sizes of their atoms are vastly different. C) they come from different sources. D) helium is most similar to other group 18 elements.

Q: About how many elements do you have access to as a consumer of market goods? A) none B) one C) ten D) one hundred

Q: Strontium, Sr (number 38), is especially dangerous to humans because it tends to accumulate in calcium-dependent bone marrow tissues (calcium, Ca, number 20). This fact relates to the organization of the periodic table in that strontium and calcium are both A) metals. B) in group 2 of the periodic table. C) made of relatively large atoms. D) soluble in water.

Q: Why isn't dirt listed in the periodic table? A) The periodic table lists only elements made of one kind of material. Dirt is a mixture of elements and compounds. B) Elements like dirt and air are so common that there is no need to list them in the periodic table. C) Dirt IS listed in the periodic table but is not easily recognized because it is listed as one of the rare earths with its old scientific name, dysprosium, symbol Dy. D) None of the above is true.

Q: Should the periodic table be memorized? Why or why not? A) Yes. Like the alphabet, we need to memorize the periodic table in order to easily write the language of chemistry. B) Yes. Without memorizing the periodic table, one would not have any real understanding of how and why chemical compounds are put together. C) No. The periodic table changes every year. Memorizing it would be a waste of time. D) No. The periodic table is a reference to be used, not memorized.

Q: Which of the following statements does not describe a proton? A) It orbits around the nucleus of an atom. B) It has a positive charge equivalent but opposite of an electron's. C) It is much more massive than an electron. D) It is a nucleon. E) It is attracted to negatively charged electrical plates.

Q: Which of the following does not describe a neutron? A) It has a positive charge equivalent but opposite of an electron's. B) It is much more massive than an electron. C) It is a nucleon. D) It is often associated with protons. E) It is more difficult to detect than a proton or an electron.

Q: The following statement describes which subatomic particle best? It has a relatively large mass. A) an electron B) a proton C) a neutron D) A and B E) B and C

Q: The following statement describes which subatomic particle best? It is electrically charged. A) an electron B) a proton C) a neutron D) A and B E) B and C

Q: The following statement describes which subatomic particle best? It is located outside of the nucleus. A) an electron B) a proton C) a neutron D) A and B E) B and C

Q: The following statement describes which subatomic particle best? It is a nucleon. A) an electron B) a proton C) a neutron D) A and B E) B and C

Q: The following statement describes which subatomic particle best? It does not have an electrical charge. A) an electron B) a proton C) a neutron D) A and B E) B and C

Q: Which element has the atomic number 9? A) F B) Ne C) B D) Na E) Be

Q: Which element has the atomic number 12? A) Mg B) C C) B D) Na E) Be

Q: Which of the following statements describes an isotope? A) element with the same number of protons but a different number of neutrons. B) element with the same number of protons but a different number of electrons. C) element with the same number of neutrons but a different number of electrons. D) element with the same number of neutrons but a different number of protons. E) none of the above

Q: The mass number of an element is A) the sum of the protons and the neutrons. B) the sum of the electrons and the protons. C) the sum of the electrons and the neutrons. D) the sum of the isotopes. E) the number of protons.

Q: What does the following element description actually mean? iron-57 A) iron with a mass number of 57 B) iron with an atomic number of 57 C) iron with 57 protons D) iron with 57 neutrons E) 57 iron atoms

Q: What does the following element description actually mean? hydrogen-2 A) a hydrogen with one neutron and one proton B) a hydrogen with two neutrons C) a hydrogen with two protons D) a molecule of hydrogen gas E) two hydrogen atoms

Q: What does the following element description actually mean? U A) a uranium atom with 92 protons and 146 neutrons B) a uranium atom with 238 neutrons and 92 protons C) a uranium atom with 92 neutrons and 238 protons D) a uranium atom with 92 neutrons and 146 protons E) none of the above

Q: What does the following element description actually mean? O A) an oxygen atom with 6 protons and 12 neutrons B) an oxygen atom with 6 neutrons and 12 protons C) 6 oxygen atoms with 18 neutrons D) 18 oxygen molecules with 6 neutrons each E) none of the above

Q: Using the following generic atom description, choose the correct method for determining the number of neutrons. X A) subtract G from F B) subtract F from G C) add F and G D) divide F by G E) look it up on the periodic table

Q: If you remove two protons and two neutrons from a gold atom (Au), what new element is formed? A) Ir B) Au C) Re D) Au-2 E) Tl

Q: If you remove two protons and two electrons from a sulfur atom (S), what new element is formed? A) Si B) Si+2 C) Al+2 D) Al E) Ar-2

Q: If an element has 15 protons and 16 neutrons and 15 electrons, what is the mass number of the element? A) 31 B) 15 C) 16 D) 30 E) none of the above

Q: If an element has 18 protons and 20 neutrons and 18 electrons, which expression correctly identifies the element? A) argon-38 B) argon-18 C) argon-20 D) calcium-38 E) calcium-20

Q: If an element has 10 protons and 11 neutrons and 10 electrons, which expression correctly identifies the element? A) neon-21 B) neon-11 C) neon-31 D) sodium-11 E) sodium-20

Q: If an element has 9 protons and 10 neutrons and 9 electrons, which expression correctly identifies the element? A) F B) F C) K D) K E) K

Q: If a neutral element has 8 neutrons and 7 electrons, which expression correctly identifies the element? A) N B) O C) O D) O E) cannot tell from information given

Q: If a neutral element has the following chemical notation, how many electrons does it have? carbon-13 A) 6 B) 12 C) 13 D) 7 E) none of the above

Q: If a neutral element has the following chemical notation, how many electrons does it have? fluorine-19 A) 9 B) 10 C) 11 D) 19 E) none of the above

Q: If a neutral element has the following chemical symbol, how many electrons does it have? O A) 6 B) 18 C) 12 D) 24 E) none of the above

Q: If a neutral element has the following chemical symbol, how many electrons does it have? U A) 92 B) 82 C) 235 D) 143 E) none of the above

Q: An element has two different isotopes: one that weighs 65 amu and another that weighs 67 amu. If the average atomic mass of all the isotopes is 66.5 amu, what can be said about the relative abundance of the isotopes? A) The isotope with the mass of 67 is more abundant than the isotope with the mass of 65. B) The isotope with the mass of 65 is more abundant than the isotope with the mass of 67. C) The isotope with the mass of 66.5 is more abundant than the isotope with the mass of 67. D) The isotope with the mass of 66.5 is more abundant than the isotope with the mass of 65. E) All the isotopes have the same relative abundance.

Q: Boron has primarily two isotopes, one with an atomic mass of 11 amu and another with an atomic mass of 10 amu. If the abundance of the boron atom with a mass of 11 amu is 18.9 percent and the abundance of the other isotope is 81.1 percent, what would be the average mass of the boron atom? A) 10.19 amu B) 11 amu C) 10 amu D) 10.81 amu E) not enough information given

Q: An element found in another galaxy exists as two isotopes. If 80.0 percent of the atoms have an atomic mass of 80.00 atomic mass units and the other 20.0 percent have an atomic mass of 82.00 atomic mass units, what is the atomic mass of the element? A) 81.0 atomic mass units B) 64.0 atomic mass units C) 80.4 atomic mass units D) 16.4 atomic mass units E) 81.6 atomic mass units

Q: Which of the following diagrams best represents the size of the atomic nucleus relative to the size of the atom? A B C D A) A B) B C) C D) D

Q: If two protons and two neutrons are removed from the nucleus of an oxygen atom, a nucleus of which element remains? A) nitrogen-12 B) carbon-12 C) neon-18 D) carbon-14

Q: You could swallow a capsule of germanium, Ge (atomic number 32), without significant ill effects. If a proton were added to each germanium nucleus, however, you would not want to swallow the capsule because the germanium would A) become arsenic. B) become radioactive. C) expand and likely lodge in your throat. D) have a change in flavor.

Q: If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? What is the name of this element? A) atomic mass, 137 amu; Barium B) atomic mass, 99 amu; Technetium C) atomic mass, 99 amu; Radon D) atomic mass 142 amu; Einsteinium

Q: The nucleus of an electrically neutral iron atom contains 26 protons. How many electrons does this iron atom have? A) 52 B) 26 C) 24 D) none

Q: Evidence for the existence of neutrons did not come until many years after the discoveries of the electron and the proton. Give a possible explanation. A) The neutron is nearly massless. B) The neutron is only slightly more massive than the proton. C) The discovery required the use of ultrafast computers. D) The neutron lacks an electrical charge.

Q: Which has more atoms: a 1-gram sample of carbon-12 or a 1-gram sample of carbon-13? A) More information is needed. B) a 1-gram sample of carbon-12 C) a 1-gram sample of carbon-13 D) They have the same number of atoms.

Q: Why are the atomic masses listed in the periodic table not whole numbers? A) Scientists have yet to make the precise measurements. B) That would be too much of a coincidence. C) The atomic masses are average atomic masses. D) Today's instruments are able to measure the atomic masses to many decimal places.

Q: Which contributes more to an atom's mass: electrons or protons? Which contributes more to an atom's size? A) Protons contribute more to an atom's mass while electrons contribute more to its size. B) Electrons contribute more to an atom's mass while protons contribute more to its size. C) Protons contribute more to both the mass and size of an atom. D) Electrons contribute more to both the mass and size of an atom.

Q: What is the approximate mass of a carbon atom in atomic mass units (amu)? How about a carbon dioxide molecule? A) A carbon atom has a mass of about 12 amu. Carbon dioxide would then have a mass of 28 amu. B) A carbon atom has a mass of about 6 amu. Carbon dioxide would then have a mass of 32 amu. C) A carbon atom has a mass of about 12 amu. Carbon dioxide would then have a mass of 44 amu. D) A carbon atom has a mass of about 6 amu. Carbon dioxide would then have a mass of 22 amu.