Final: Ch 12 – Flashcards
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A cat strolls across your backyard. An hour later, a dog with its nose to the ground follows the trail of the cat. Explain what is going on from a molecular point of view.
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The dog is smelling MOLECULES from the cat.
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If all the molecules of a body remained part of that body, would the body have any odor?
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No, because there would be no molecules traveling to our nose.
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Which are older, the atoms in the body of an elderly person or those in the body of a baby?
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They are of the same age, which is appreciable older than the solar system.
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Where did the atoms that make up a newborn baby originate?
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In the explosions of ancient
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In what sense can you truthfully say that you are a part of every person around you?
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We are continually exchanging our atoms.
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Considering how small atoms are, what are the chances that at least one of the atoms exhaled in your first breath will be in your last breath?
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VERY PROBABLE because of how incredibly small atoms are
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Does it make sense to say that a textbook is about 99.9 percent empty space?
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YES A textbook like all material things is made up of atoms, which are considered to be 99.9 percent empty space.
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Since atoms are mostly empty space, why don't objects pass through one another?
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The electrons on the atom repel other electrons on other atoms when they get close.
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How do we account for the great variety of substances in the world?
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There are many possible combinations of atoms.
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Which of the following statements best describes an element?
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A material consisting of only one type of atom
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A beam of protons and a beam of neutrons of the same energy are both harmful to living tissue. The beam of neutrons, however, is less harmful. Why?
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Neutrons carry no electric charge and thus have a greater likelihood of passing through the tissue.
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The element bromine, Br (atomic number 35), has two major isotopes of similar abundance, both around 50 percent. The atomic mass of bromine is reported in the periodic table as 79.904 atomic mass units. Choose the most likely set of mass numbers for these two bromine isotopes.
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Br-79, Br-81
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The isotope lithium-7 has a mass of 7.0160 atomic mass units, and the isotope lithium-6 has a mass of 6.0151 atomic mass units. Given the information that 92.58 percent of all lithium atoms found in nature are lithium-7 and 7.42 percent are lithium-6, calculate the atomic mass of lithium, Li (atomic number 3).
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6.942 amu
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When we breathe we inhale oxygen, O2, and exhale carbon dioxide, CO2, plus water vapor, H2O. Which likely has more mass, the air that we inhale or the same volume of air we exhale? Does breathing cause you to lose or gain weight?
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The air we exhale has more mass; Breathing causes you to lose weight.
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What is the approximate mass of a carbon atom in atomic mass units (amu)? How about a carbon dioxide molecule?
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A carbon atom has a mass of about 12 amu. Carbon dioxide would then have a mass of 44 amu.
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Which contributes more to an atom's mass: electrons or protons? Which contributes more to an atom's size?
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Protons contribute more to an atom's mass while electrons contribute more to its size.
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Why are the atomic masses listed in the periodic table not whole numbers?
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The atomic masses are average atomic masses.
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Which has more atoms: a 1-gram sample of carbon-12 or a 1-gram sample of carbon-13?
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a 1-gram sample of carbon-12
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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.
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The neutron lacks an electrical charge.
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The nucleus of an electrically neutral iron atom contains 26 protons. How many electrons does this iron atom have?
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26
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If an atom has 43 electrons, 56 neutrons, and 43 protons, what is its approximate atomic mass? What is the name of this element?
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Atomic mass, 99 amu; technetium
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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
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become arsenic
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If two protons and two neutrons are removed from the nucleus of an oxygen atom, a nucleus of which element remains?
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carbon-12
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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?
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80.4 atomic mass units
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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?
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10.19 amu
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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?
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The isotope with the mass of 67 is more abundant than the isotope with the mass of 65.
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If a neutral element has the following chemical notation, how many electrons does it have? fluorine-19
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9
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If a neutral element has the following chemical notation, how many electrons does it have? carbon-13
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6
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If a neutral element has 8 neutrons and 7 electrons, which expression correctly identifies the element?
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15/7 N
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If an element has 10 protons and 11 neutrons and 10 electrons, which expression correctly identifies the element?
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neon-21
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If an element has 18 protons and 20 neutrons and 18 electrons, which expression correctly identifies the element?
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argon-38
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If an element has 15 protons and 16 neutrons and 15 electrons, what is the atomic mass of the element?
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31
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If you remove two protons and two electrons from a sulfur atom (S), what new element is formed?
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Si
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If you remove two protons and two neutrons from a gold atom (Au), what new element is formed (if any)?
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Ir
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Using the following generic atom description, choose the correct method for determining the number of neutrons. F G X
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subtract G from F
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What does the following element description actually mean? 18 6 O
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an oxygen atom with 6 protons and 12 neutrons
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What does the following element description actually mean? hydrogen-2
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a hydrogen with one neutron and one proton
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What does the following element description actually mean? iron-57
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iron with a mass number of 57
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The mass number of an element is ________.
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sum of protons and neutrons
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Which of the following statements describes an isotope?
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element with the same number of protons but a different number of neutrons
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Which element has the atomic number 12?
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Mg
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Which element has the atomic number 9?
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F
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The following statement describes which subatomic particle best? It does not have an electrical charge.
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neutron
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The following statement describes which subatomic particle best? It is a nucleon.
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proton, neutron
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The following statement describes which subatomic particle best? It is located outside of the nucleus.
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an electron
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The following statement describes which subatomic particle best? It is electrically charged
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electron, proton
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The following statement describes which subatomic particle best? It has a relatively large mass.
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proton, neutron
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Which of the following does not describe a neutron?
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it has a positive charge equivalent but opposite of an electrons
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Which of the following statements does not describe a proton?
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It orbits around the nucleus of an atom.
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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
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in group 2 of the periodic table
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About how many elements do you have access to as a consumer of market goods.
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ten
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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
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helium is most similar to other group 18 elements
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What happens to the properties of elements across any period of the periodic table?
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The properties of the elements gradually change across any period of the periodic table.
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Which of the following physical properties would you expect for krypton (Kr)?
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a gas at room temperature
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Which of the following elements will most likely be shiny and flexible?
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rhodium (Rh)
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Which of the following elements is in the fourth period?
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chromium (Cr)
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Which of the following elements is a transition metal?
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silver (Ag)
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Which of the following elements is an alkali metal?
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lithium (Li)
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Which of the following elements is a halogen?
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chlorine (Cl)
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Which of the following elements is a gas at room temperature?
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argon (Ar)
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The repeating trends that take place when examining the elements are called ________.
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periodicity
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Which element would have chemical properties the most similar to chlorine (Cl)?
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Br
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Which chemical family is composed almost entirely of man-made elements?
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actinides
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Which of the following is not the name of a chemical family?
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heavy metals
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Elements that are in the same ________ have a tendency to have very similar chemical properties due to periodic trends.
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group
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Which of the following elements are in the same group as silicon (Si)?
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C
