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AC Unit 3 Atoms & Periodic Table Study Guide - Answer Sheet1)Identify the number of neutrons in one atom of sulfur with an isotopic mass number of 34 amu.A)16B)18C)32D)34Explanation:One atom of sulfur with an isotopic mass number of 34 has?18?neutrons. 34 (total) - 16 (protons) = 18 (neutrons).2)?Which substance is an example of an element?A)bronzeB)copperC)methaneD)rustExplanation:Copper?is an element, the others are all compounds, or a combination of several elements.3)?In atoms, electrons surround the nucleus inA)random patterns.B)specific energy levels.C)orbits like the planets.D)a "plum pudding" type arrangement.Explanation:Electrons are ordered in?specific energy levels?around the nucleus. The more energy they have, the further the negative electrons can be from the positive nucleus.4)An atom of hydrogen consists of one _______________ surrounded by one _________________.A)proton, neutronB)neutron, protonC)proton, electronD)neutron, electronExplanation:One?proton?defines the nucleus of a hydrogen atom, as is identified by the atomic number 1. One?electron?surrounds the proton and balances its charge. If there were any neutrons, the mass of the hydrogen would be around 2 amu.5)?At the center of every atom lies a small, dense ____________ that is positively charged.A)cloudB)neutronC)nucleusD)orbitalExplanation:The?nucleus?is the very tiny, very dense center of the atom which contains all of the atoms protons and neutrons - most of its mass - but very little of its volume. Think about a marble at the center of a football field.6)Neon's outer energy level contains ______________ electrons.A)2B)8C)10D)20Explanation:Neon is in the last family on the periodic table, and belongs to the "Noble Gases". The noble gases are stable and don't mix with other elements (like nobility did not mix with commoners). The reason it is so stable is because it has?8?outer energy level, valence, electrons. Look at the last ring around the atom.7)What is the atomic number of the atom shown?A)3B)13C)14D)27Explanation:The atomic number is the whole number that is used to order the elements in the periodic table which is based on the number of protons. In the case of the atom above, aluminum, there are 13 protons, so the atomic number is also?13.8)An atom of the element ____________has an average atomic mass of about 16 amu.A)oxygenB)sulfurC)nitrogenD)no elements have that massExplanation:Oxygen?has a mass of approximately 16 amu. Use the non-whole number from the periodic table 15.9994amu for oxygen and round properly up to 16 amu.9)Twenty is the _________________ of potassium.A)chargeB)atomic massC)atomic numberD)number of neutronsExplanation:Potassium has an atomic number (of protons) of 19. Subtract this from the atomic mass, 39, and you are left with 20, the?number of neutrons.10)?An equal number of protons and neutrons in an atom typically results in an atom that isA)negatively charged.B)positively charged.C)electrically neutral.D)radioactively stable.Explanation:It is the balance between protons and neutrons that makes the nucleus of atoms very?radioactively stable. They are held together with the strong nuclear force.11)?Which is an example of an element?A)salt (NaCl)B)water (H20)C)silver (Ag)D)electron (e-)Explanation:Silver (Ag)?is the only thing listed that is found on the periodic table and is one of the basic 116 elements or so.12)?Which of the diagrams is the correct model for the element beryllium?A)B)C)D)Explanation:B?is correct because it shows the correct number of protons and neutrons tightly packed in the nucleus and the electrons arranged in unique energy levels around the nucleus.13)?Elements in the same group/family of the periodic table are similar in what way?A)They are all metalsB)They are all nonmetalsC)They have a full outer shell of electrons.D)They have the same number of valence electrons.Explanation:They have the same number of valence.?This makes them similar in terms of reactability predictions and properties.14)?An atom of calcium-48 and an atom of calcium-47 differ inA)atomic number.B)nuclear charge.C)number of neutrons.D)number of electrons.Explanation:The correct answer is?number of neutrons. The sum of the protons and neutrons equals the mass numbers, 47 and 48. All isotopes of calcium have 20 protons.15)How many electrons are in an electrically neutral atom of boron?A)3B)5C)6D)8Explanation:In any atom, the number of electrons is equal to the number of protons. The number of protons can be determined by looking at the atomic number from the periodic table. In the case of boron, there are?5?protons, so there are also 5 electrons. (3 in the outer energy level.)16)?Which part of the atom cannot have its location accurately determined and is modeled by a cloud around the center of the atom?A)electronB)neutronC)nucleusD)protonExplanation:Electrons?are moving rapidly and randomly around the nucleus. Their exact location is impossible to determine accurately, so it is modeled as a cloud around the nucleus.17)?The red arrow is pointed at different locations of an atom of Helium. Where is it pointing to the GREATEST concentration of atomic mass?A)B)C)D)Explanation:Arrow?A?is pointing to the GREATEST area of mass concentration, the nucleus.18)Beryllium has a nucleus composed of protons and neutrons. Given the data, how many neutrons are in a typical Beryllium nucleus?A)3B)4C)5D)9Explanation:There are?5?neutrons in the nucleus. Subtract the atomic number (4) from the average atomic mass (9) to obtain your answer.19)ProtonsNeutronsWhich statement is accurate for these two sub-atomic particles.A)They both have a neutral charge.B)They both have a positive charge.C)They are both located in the nucleus.D)They are both located outside the nucleus.Explanation:They are both located in the nucleus.?A proton has a positive charge and a neutron has a neutral charge. An electron is located outside the nucleus and has a negative charge.20)?Which is MOST LIKELY a solid at room temperature?A)chlorineB)hydrogenC)neonD)potassiumExplanation:Potassium?is the only solid listed. All of the others are gases. If you look at the periodic table, potassium is listed on the left and is classified with all the other metals. All the rest are on the right with the nonmetals.21)Oxygen and Fluorine Familyoxygen8O15.999fluorine9F18.998sulfur16S32.065chlorine17Cl35.453selenium34Se78.96bromine35Br79.904tellurium52Te127.60iodine53I126.90polonium84Po[209]astatine85At[210]When studying the halogens (group 17) on the periodic table, how does the number of the valence electrons change as the energy level is increased?A)The total number of valence electrons does not change, it remains 7.B)The total number of valence electrons does not change, it remains 1.C)The total number of valence electrons increases by 1 with each energy level.D)The total number of valence electrons decreases by 1 with each energy level.Explanation:The total number of valence electrons does not change, it remains 7.?Families in the periodic table share chemical characteristics because they have the same number of valence electrons. For halogens, this is 7.22)What element behaves MOST like magnesium?A)SB)SiC)SnD)SrExplanation:Sr?behaves MOST like magnesium because it is in the same family, the alkaline earth metals. Members of the same family have the same number of valence electrons; this is an important reason why they behave alike.23)Some common substances used in the laboratory are listed in the table. The chemical formulas of the substances are also listed beside their names.How many of the listed items are elements?A)3B)4C)5D)6Explanation:5?Copper, sulfur, gold, iron, and aluminum are elements, as their symbols suggest. The other four substances are compound with two elements each.24)Based on its location in the periodic table, we know that ALL BUT one property applies to the element radon. Which property does not apply to radon?A)syntheticB)radioactiveC)nonreactiveD)gas at room temperatureExplanation:Radon is a nonreactive gas that is radioactive. Radon is not?synthetic.?Elements with an atomic number of 93 or greater are synthetic. Radon's atomic number is 86, is naturally occurring, and is considered a health threat as it is an indoor air contaminant.25)What is the atomic number of the atom shown?A)8B)12C)18D)39.948Explanation:The atomic number is the whole number that is used to order the elements in the periodic table which is based on the number of protons. In the case of the atom above, argon, there are 18 protons, so the atomic number is also?18.26)?The atomic number of magnesium is 12. This means that its nucleus must containA)6 protons and 6 neutrons.B)6 neutrons and 6 electrons.C)12 neutrons and no protons.D)12 protons and no electrons.Explanation:The atomic number of magnesium is 12. Its nucleus must contain?12 protons and no electrons. The atomic number of an atom is determined by the number of protons. Electrons are not in the nucleus.27)Which two locations are MOST probable for locating the cloud of electrons?A)A and BB)B and CC)C and DD)D and AExplanation:The two most probable locations are?C and D. This is outside the nucleus on the first and second energy levels.28)?Protons are positively charged and repel other protons. Which other particle is found in the nucleus and separates protons so that the strong force can hold the nucleus together?A)electronsB)neutronsC)protonsD)quarksExplanation:neutrons?are neutral and will separate the protons so that they do not repel.29)Using the periodic table and your knowledge of atomic structure. cobalt (Co) and nickel (Ni) have almost identical atomic mass numbers. Comparing the a typical nickel and cobalt atoms, which statement best describes the atoms?A)Nickel has one more neutron.B)Cobalt has one less proton.C)Both atoms will have the same number of protons.D)Both atoms will have the same number of neutrons.Explanation:Each atom has same mass, but cobalt has?one less proton. The number of protons are used to identify the element because that is also the atomic number.30)?The element sodium has an atomic number of 11 and a mass number of 23. How many protons, neutrons, and electrons does one atom contain?A)11p+, 11e-, 12noB)11p+, 12e-, 11noC)11p+, 11e-, 23noD)12p+, 12e-, 11noExplanation:The atomic number tells you how many protons are in the nucleus. In a neutral atom, the number of protons is the same as the number of electrons. Since the atomic number of sodium is 11,the atom contains 11 protons and 11 electrons.?The number of neutrons is determined by subtracting the atomic number from the mass number. This means that sodium has 12 neutrons.31)?Which statement about atomic structure is incorrect?A)Protons are located in the nucleus.B)Protons and electrons have the same mass.C)Protons and electrons have opposite charges.D)Neutral atoms contain the same number of protons and electrons.Explanation:In a neutral atom, protons and electrons are equal in number and charge.?Protons and electrons do NOT have the same mass.Protons are considerably larger than electrons. Protons and neutrons have the same mass.32)Which part of the diagram represents the proton?A)AB)BC)CD)DExplanation:The proton is located in the nucleus and has a positive charge. The letter indicating the proton is?C.33)Atomic StructureElementAtomic NumberNumber of ProtonsNumber of ElectronsNumber of NeutronsMass NumberCarbon1288Hydrogen110Using the chart above, determine which statement would be FALSE.A)Carbon would have 6 protons.B)Hydrogen would have 0 neutrons.C)Each element would have a mass number of 12.D)Neon is the element with an atomic number of 10.Explanation:Mass number is determined by the numbe rof protons and neutrons in the nucleus of the atom. Therefore, the statement?each element would have a mass number of 12?would be false.34)?The _________ contains the majority of the mass of the atom but is much ________ than the atom.A)nucleus, smallerB)neutrons, largerC)electron cloud, smallerD)pions and quarks, largerExplanation:nucleus, smaller.?Remember that the nucleus contains both protons and neutrons and therefore most of the mass of the atom but is very small compared to the size of the atom.35)?All the elements of a family in the periodic table have what feature in common?A)They all have similar chemical properties.B)They all have the same number of protons in the nucleus.C)They are all located in the same horizontal row or period.D)They all have the same number of electrons in the electron cloud.Explanation:Elements of any family in the periodic table have the same number of valence electrons. Because of this?they all have similar chemical properties.36)Which part of the diagram represents the nucleus?A)AB)BC)CD)DExplanation:The nucleus is the central portion of the atom. The nucleus contains the protons and the neutrons. Therefore, the portion of the diagram that is the nucleus is?D.37)Using the periodic table and your knowledge of atomic structure. Would Carbon-14 have more, less or the same number of neutrons as a typical carbon atom? How do you know?A)The same number of neutrons. All carbon atoms have atomic number 6.B)The periodic table cannot give you the information needed to answer this question.C)It has less neutrons. Its mass number is smaller than the one on the periodic table.D)It has more neutrons. Its mass number is larger than the atomic mass number for carbon.Explanation:Carbon-14 has a mass number of 14.?It has more neutrons. Its mass number is larger than the atomic mass number for carbon.38)Using the periodic table and your knowledge of atomic structure. Compare the number of electrons in a Carbon-12 and Carbon-14 isotope.A)Both have 6 electrons.B)Carbon-12 has 6 electrons and Carbon-14 has 8 electrons.C)Carbon-12 has no electrons and Carbon-14 has 2 electrons.D)Carbon-12 has 12 electrons and Carbon-14 has 14 electrons.Explanation:Every Caebon atoms has 6 electrons. So,?both have 6 electrons.39)?An atom with an atomic number of 12 and a mass number of 25 can best be described by which of these?A)An atom that contains 12 protons and 13 neutrons.B)An atom that contains 13 protons and 12 neutrons.C)An atom that contains 12 protons and 25 neutrons.D)An atom that contains 25 protons and 12 neutrons.Explanation:An atom that contains 12 protons and 13 neutrons.?Atomic number is the number of protons and mass number = atomic number + neutrons.40)?Elaborate what knowing that carbon-14 has an atomic number of 6 tells us about the atom.A)Carbon-14 contains 6 baryons, 7 prions, and 8 neutrons.B)Carbon-14 contains 7 electrons, 7 protons, and 7 quarks.C)Carbon-14 contains 6 electrons, 6 protons, and 8 neutrons.D)Carbon-14 contains 8 electrons, 6 photons, and 6 neutrons.Explanation:Carbon-14 contains 6 electrons, 6 protons, and 8 neutrons.?The 14 in the name indicates the mass number. The atomic number gives both the number of protons and the number of electrons.Mass number - atomic number = number of neutrons. So 14 - 6 = 8 neutrons. ................
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