Open Question
When two protons fuse in a star, the product is ²H plus a positron. Write the nuclear equation for this process.
Ch.21 - Nuclear Chemistry
Chapter 21, Problem 79
According to current regulations, the maximum permissible dose of strontium-90 in the body of an adult is 1 mCi (1 * 10^-3 Ci). Using the relationship rate = kN, calculate the number of atoms of strontium-90 to which this dose corresponds. To what mass of strontium-90 does this correspond? The half-life for strontium-90 is 28.8 years.
Verified step by step guidance1
Step 1: Understand the relationship rate = kN, where 'rate' is the activity in curies (Ci), 'k' is the decay constant, and 'N' is the number of radioactive atoms. The activity given is 1 mCi, which is 1 * 10^{-3} Ci.
Step 2: Calculate the decay constant 'k' using the half-life formula: k = \frac{0.693}{t_{1/2}}, where t_{1/2} is the half-life of strontium-90, which is 28.8 years. Convert the half-life into seconds for consistency in units.
Step 3: Substitute the values of 'rate' and 'k' into the equation rate = kN to solve for 'N', the number of atoms of strontium-90.
Step 4: Use Avogadro's number (6.022 * 10^{23} atoms/mol) to convert the number of atoms 'N' to moles of strontium-90.
Step 5: Calculate the mass of strontium-90 by multiplying the moles obtained in Step 4 by the molar mass of strontium-90, which is approximately 89.9077 g/mol.
Related Practice
Textbook Question
Nuclear scientists have synthesized approximately 1600 nuclei not known in nature. More might be discovered with heavy-ion bombardment using high-energy particle accelerators. Complete and balance the following reactions, which involve heavy-ion bombardments:
(a) 63Li + 5628Ni → ?
(b) 4020Ca + 24896Cm → 14762Sm + ?
(c) 8838Sr + 8436Kr → 11646Pd + ?
(d) 4020Ca + 23892U → 7030Zn + 4 10n + 2 ?
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Textbook Question
In 2010, a team of scientists from Russia and the United States reported creation of the first atom of element 117, which is named tennessine, and whose symbol is Ts. The synthesis involved the collision of a target of 24997Bk with accelerated ions of an isotope which we will denote Q. The product atom, which we will call Z, immediately releases neutrons and forms 294117Ts: 24997Bk + Q → Z → 294117Ts + 3 10n (b) Isotope Q is unusual in that it is very long-lived (its half-life is on the order of 1019 yr) in spite of having an unfavorable neutron-to-proton ratio (Figure 21.1). Can you propose a reason for its unusual stability?
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Textbook Question
Each of the following transmutations produces a radionuclide used in positron emission tomography (PET).
(a) In equations (i) and (ii), identify the species signified as 'X.'
(i) 14N(p,α)X
(ii) 18O(p,X)18F
(iii) 14N(d,n)15O
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Textbook Question
The nuclear masses of 7Be, 9Be, and 10Be are 7.0147, 9.0100, and 10.0113 amu, respectively. Which of these nuclei has the largest binding energy per nucleon?
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Open Question
A 26.00-g sample of water containing tritium, ³¹H, emits 1.50 * 10³ beta particles per second. Tritium is a weak beta emitter with a half-life of 12.3 years. What fraction of all the hydrogen in the water sample is tritium?