Questions and Answers of Atomic And Nuclear Physics

Uranium-238 can absorb a neutron and undergo a fission reaction to produce an atom of cesium-135 and an atom of rubidium-96. Write the balanced nuclear equation for the process and determine the
The nuclear equation for the fission of uranium-238 is as follows:
Francium has an atomic number of 87. Write the nuclear equation for the alpha particle emission of francium-212. What is the daughter isotope?
Tin has an atomic number of 50. Write the nuclear equation for the beta particle emission of tin-121. What is the daughter isotope?
Technetium has an atomic number of 43. Write the nuclear equation for the beta particle emission of technetium-99. What is the daughter isotope?
Energies of gamma rays are typically expressed in units of megaelectron volts (MeV), where 1 MeV = 1.602 ( 10−13 J. Using the data provided in the text, calculate the energy in megaelectron volts
The gamma ray emitted when oxygen-19 gives off a beta particle is 0.197 MeV. What is its energy in joules? (See Exercise 13 for the definition of a megaelectron volt.)
How many protons and neutrons are in each isotope?c. 56Fed. 224Rn
How many protons and neutrons are in each isotope?c. 252Es d. 40K
Plutonium has an atomic number of 94. Write the nuclear equation for the alpha particle emission of plutonium-244. What is the daughter isotope?
An artifact containing carbon-14 contains 8.4 × 10−9 g of carbon-14 in it. If the age of the artifact is 11,670 y, how much carbon-14 did it have originally? The half-life of carbon-14 is 5,730 y.
Carbon-11 is a radioactive isotope used in positron emission tomography (PET) scans for medical diagnosis. Positron emission is another, though rare, type of radioactivity. The half-life of carbon-11
How long does it take for 1.00 g of palladium-103 to decay to 0.125 g if its half-life is 17.0 d?
How long does it take for 2.00 g of niobium-94 to decay to 0.0625 g if its half-life is 20,000 y?
It took 75 y for 10.0 g of a radioactive isotope to decay to 1.25 g. What is the half-life of this isotope?
It took 49.2 s for 3.000 g of a radioactive isotope to decay to 0.1875 g. What is the half-life of this isotope?
The half-life of americium-241 is 432 y. If 0.0002 g of americium-241 is present in a smoke detector at the date of manufacture, what mass of americium-241 is present after 100.0 y? After 1,000.0 y?
If the half-life of tritium (hydrogen-3) is 12.3 y, how much of a 0.00444 g sample of tritium is present after 5.0 y? After 250.0 y?
How long does it take 100.0 mCi of fluorine-20 to decay to 10.0 mCi if its half-life is 11.0 s?
Technetium-99 is used in medicine as a source of radiation. A typical dose is 25 mCi. How long does it take for the activity to reduce to 0.100 mCi? The half-life of 99Tc is 210,000 y.
Use Table 15.4 to determine which sources of radiation exposure are inescapable and which can be avoided. What percentage of radiation is unavoidable?
Explain how a Geiger counter works to detect radiation.
A sample of radon gas has an activity of 140.0 mCi. If the half-life of radon is 1,500 y, how long before the activity of the sample is 8.75 mCi?
A sample of curium has an activity of 1,600 Bq. If the half-life of curium is 24.0 s, how long before its activity is 25.0 Bq?
If a radioactive sample has an activity of 65 µCi, how many disintegrations per second are occurring?
Define tracer and give an example of how tracers work.
Explain how radioactive dating works.
The current disintegration rate for carbon-14 is 14.0 Bq. A sample of burnt wood discovered in an archeological excavation is found to have a carbon-14 disintegration rate of 3.5 Bq. If the half-life
A small asteroid crashes to Earth. After chemical analysis, it is found to contain 1 g of technetium-99 to every 3 g of ruthenium-99, its daughter isotope. If the half-life of technetium-99 is
A process called helium burning is thought to occur inside older stars, forming carbon:34He ( 12CIf the reaction proceeds with 0.00781 g of mass lost on a molar basis, how much energy is given off?
Briefly describe how a nuclear reactor generates electricity.
Briefly describe the difference between how a nuclear reactor works and how a nuclear bomb works.
How much matter needs to be converted to energy to supply 400 kJ of energy, the approximate energy of 1 mol of C–H bonds? What conclusion does this suggest about energy changes of chemical
In the spontaneous fission of lead-208, the following reaction occurs:208Pb ( 129I + 76Cu + 31nFor every mole of lead-208 that decays, 0.1002 g of mass is lost. How much energy is given off per mole
In the spontaneous fission of radium-226, the following reaction occurs:226Ra ( 156Pm + 68Co + 21nFor every mole of radium-226 that decays, 0.1330 g of mass is lost. How much energy is given off per
Recalculate the amount of energy from Exercise 3 in terms of the number of grams of lead-208 reacted.
Recalculate the amount of energy from Exercise 4 in terms of the number of grams of radium-226 reacted.
What is the energy change of this fission reaction? Masses in grams are provided.
What is the energy change of this fission reaction? Masses in grams are provided.
The two rarer isotopes of hydrogen—deuterium and tritium—can also be fused to make helium by the following reaction:2H + 3H ( 4He + 1nIn the course of this reaction, 0.01888 g of mass is lost.
Smoke detectors typically contain about 0.25 mg of americium-241 as part of the smoke detection mechanism. If the activity of 1 g of americium-241 is 1.26 ( 1011 Bq, what is the activity of
Uranium hexafluoride (UF6) reacts with water to make uranyl fluoride (UO2F2) and HF. Balance the following reaction: UF6 + H2O ( UO2F2 + HF
The cyclopentadienyl anion (C5H5−) is an organic ion that can make ionic compounds with positive ions of radioactive elements, such as Np3+. Balance the following reaction: NpCl3 + Be(C5H5)2 (
If the half-life of hydrogen-3 is 12.3 y, how much time does it take for 99.0% of a sample of hydrogen-3 to decay?
If the half-life of carbon-14 is 5,730 y, how long does it take for 10.0% of a sample of carbon-14 to decay?
Although bismuth is generally considered stable, its only natural isotope, bismuth-209, is estimated to have a half-life of 1.9 × 1019 y. If the universe is estimated to have a lifetime of 1.38 ×
The most common isotope of uranium (uranium-238) has a half-life of 4.5 × 109 y. If the universe is estimated to have a lifetime of 1.38 × 1010 y, what percentage of uranium-238 has decayed over
Refer to Table 15.3 and separate the sources of radioactive exposure into voluntary and involuntary sources. What percentage of radioactive exposure is involuntary?
Uranium can be separated from its daughter isotope thorium by dissolving a sample in acid and adding sodium iodide, which precipitates thorium(III) iodide:Th3+(aq) + 3I−(aq) ( ThI3(s)
Thorium oxide can be dissolved in acidic solution:ThO2(s) + 4H+ ( Th4+(aq) + 2H2O(ℓ)How many milliliters of 1.55 M HCl(aq) are needed to dissolve 10.65 g of ThO2?
Radioactive strontium is dangerous because it can chemically replace calcium in the human body. The bones are particularly susceptible to radiation damage. Write the nuclear equation for the beta
Give the names and charges of the cation and anion in each of the following compounds: (a) CuS (b) Ag2SO4 (c) Al(ClO3)3 (d) Co(OH)2 (e) PbCO3.
Name the following ionic compounds: (a) Li2O (b) FeCl3 (c) NaClO (d) CaSO3 (e) Cu(OH)2 (f) Fe(NO3)2 (g) Ca(CH3COO)2 (h) Cr2(CO3)3 (i) K2CrO4 (j) (NH4)2SO4.
Name the following ionic compounds: (a) KCN (b) NaBrO2 (c) Sr(OH)2 (d) CoS (e) Fe2(CO3)3 (f) Cr(NO3)3 (g) (NH4)2SO3 (h) NaH2PO4 (i) KMnO4 (j) Ag2Cr2O7.
Write the chemical formulas for the following compounds: (a) Aluminum hydroxide (b) Potassium sulfate (c) Copper(I) oxide (d) Zinc nitrate (e) Mercury(II) bromide (f) Iron(III) carbonate (g) Sodium
Give the chemical formula for each of the following ionic compounds: (a) Sodium phosphate (b) Zinc nitrate (c) Barium bromate (d) Iron(II) perchlorate (e) Cobalt(II) hydrogen carbonate (f)
Give the name or chemical formula, as appropriate, for each of the following acids: (a) HBrO3 (b) HBr (c) H3PO4 (d) Hypochlorous acid (e) Iodic acid (f) Sulfurous acid.
Five of the boxes in the following periodic table are colored. Predict the charge on the ion associated with each of these elements.
Provide the name or chemical formula, as appropriate, for each of the following acids: (a) Hydroiodic acid (b) Chloric acid (c) Nitrous acid (d) H2CO3 (e) HClO4 (f) CH3COOH
Give the name or chemical formula, as appropriate, for each of the following binary molecular substances: (a) SF6 (b) IF5 (c) XeO3 (d) Dinitrogen tetroxide (e) Hydrogen cyanide (f) Tetraphosphorus
The oxides of nitrogen are very important components in urban air pollution. Name each of the following compounds: (a) N2O (b) NO (c) NO2 (d) N2O5 (e) N2O4.
Write the chemical formula for each substance mentioned in the following word descriptions (use the front inside cover to find the symbols for the elements you don't know). (a) Zinc carbonate can be
Assume that you encounter the following sentences in your reading. What is the chemical formula for each substance mentioned? (a) Sodium hydrogen carbonate is used as a deodorant.
(a) What is a hydrocarbon? (b) Butane is the alkane with a chain of four carbon atoms. Write a structural formula for this compound and determine its molecular and empirical formulas.
(a) What ending is used for the names of alkanes? (b) Hexane is an alkane whose structural formula has all its carbon atoms in a straight chain. Draw the structural formula for this compound and
(a) What is a functional group? (b) What functional group characterizes an alcohol? (c) With reference to Exercise 2.75, write a structural formula for 1-butanol, the alcohol derived from butane, by
(a) What do ethane and ethanol have in common? (b) How does 1-propanol differ from propane?
Chloropropane is a compound derived from propane by substituting Cl for H on one of the carbon atoms. (a) Draw the structural formulas for the two isomers of chloropropane. (b) Suggest names for
The following diagram represents an ionic compound in which the red spheres represent cations and blue spheres represent anions. Which of the following formulas is consistent with the drawing: KBr,
Draw the structural formulas for three isomers of pentane, C5H12.
Suppose a scientist repeats the Millikan oil-drop experiment but reports the charges on the drops using an unusual (and imaginary) unit called the warmomb (wa). The scientist obtains the following
The natural abundance of 3He is 0.000137$. (a) How many protons, neutrons, and electrons are in an atom of 3He? (b) Based on the sum of the masses of their subatomic particles, which is expected to
A cube of gold that is 1.00 cm on a side has a mass of 19.3 g. A single gold atom has a mass of 197.0 amu. (a) How many gold atoms are in the cube? (b) From the information given, estimate the
The diameter of a rubidium atom is 4.94 Ã…. We will consider two different ways of placing the atoms on a surface. In arrangement A, all the atoms are lined up with one another to form a
(a) Assuming the dimensions of the nucleus and atom shown in Figure 2.11, what fraction of the volume of the atom is taken up by the nucleus? (b) Using the mass of the proton from Table 2.1 and
Identify the element represented by each of the following symbols and give the number of protons and neutrons in each:
The element oxygen has three naturally occurring isotopes, with 8, 9, and 10 neutrons in the nucleus, respectively. (a) Write the full chemical symbols for these three isotopes. (b) Describe the
Use Coulomb's law, F = kQ1Q2/d2, to calculate the electric force on an electron (Q = - 1.6 × 10-10 C) exerted by a single proton if the particles are 0.53 × 10-10 m apart. The constant k in
The element lead (Pb) consists of four naturally occurring isotopes with atomic masses 203.97302, 205.97444, 206.97587, and 207.97663 amu. The relative abundances of these four isotopes are 1.4,
How does Dalton's atomic theory account for the fact that when 1.000 g of water is decomposed into its elements, 0.111 g of hydrogen and 0.889 g of oxygen are obtained regardless of the source of the
Gallium (Ga) consists of two naturally occurring isotopes with masses of 68.926 and 70.925 amu. (a) How many protons and neutrons are in the nucleus of each isotope? Write the complete atomic symbol
Using a suitable reference such as the CRC Handbook of Chemistry and Physics or www.webelements.com, look up the following information for nickel: (a) The number of known isotopes (b) The atomic
There are two different isotopes of bromine atoms. Under normal conditions, elemental bromine consists of Br2 molecules, and the mass of a Br2 molecule is the sum of the masses of the two atoms in
It is common in mass spectrometry to assume that the mass of a cation is the same as that of its parent atom. (a) Using data in Table 2.1, determine the number of significant figures that must be
From the following list of elements-Ar, H, Ga, Al, Ca, Br, Ge, K, O-pick the one that best fits each description. Use each element only once: (a) An alkali metal (b) An alkaline earth metal (c) A
The first atoms of seaborgium (Sg) were identified in 1974. The longest-lived isotope of Sg has a mass number of 266. (a) How many protons, electrons, and neutrons are in an 266Sg atom? (b) Atoms of
The explosion of an atomic bomb releases many radioactive isotopes, including strontium-90. Considering the location of strontium in the periodic table, suggest a reason for the fact that this
From the molecular structures shown here, identify the one that corresponds to each of the following species:(a) Chlorine gas(b) Propane(c) Nitrate ion(d) Sulfur trioxide(e) Methyl chloride, CH3Cl.
Name each of the following oxides. Assuming that the compounds are ionic, what charge is associated with the metallic element in each case? (a) NiO (b) MnO2 (c) Cr2O3 (d) MoO3.
Fill in the blanks in the following table:
A charged particle is caused to move between two electrically charged plates, as shown here.(a)Why does the path of the charged particle bend? (b)What is the sign of the electrical charge on the
Hydrogen sulfide is composed of two elements: hydrogen and sulfur. In an experiment, 6.500 g of hydrogen sulfide is fully decomposed into its elements. (a) If 0.384 g of hydrogen is obtained in this
Carbonic acid occurs in carbonated beverages. When allowed to react with lithium hydroxide it produces lithium carbonate. Lithium carbonate is used to treat depression and bipolar disorder. Write
Give the chemical names of each of the following familiar compounds: (a) NaCl (table salt) (b) NaHCO3 (baking soda) (c) NaOCl (in many bleaches) (d) NaOH (caustic soda) (e) (NH4)2CO3 (smelling
Many familiar substances have common, unsystematic names. For each of the following, give the correct systematic name: (a) Saltpeter, KNO3; (b) Soda ash, Na2CO3 (c) Lime, CaO (d) Muriatic acid,
Because many ions and compounds have very similar names, there is great potential for confusing them. Write the correct chemical formulas to distinguish between (a) Calcium sulfide and calcium
The compound cyclohexane is an alkane in which six carbon atoms form a ring. The partial structural formula of the compound is as follows:(a) Complete the structural formula for cyclohexane. (b) Is
A chemist finds that 30.82 g of nitrogen will react with 17.60 g, 35.20 g, 70.40 g, or 88.00 g of oxygen to form four different compounds. (a) Calculate the mass of oxygen per gram of nitrogen in
In a series of experiments, a chemist prepared three different compounds that contain only iodine and fluorine and determined the mass of each element in each compound:(a) Calculate the mass of
Summarize the evidence used by J. J. Thomson to argue that cathode rays consist of negatively charged particles.

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