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Ch.21 - Nuclear Chemistry
Chapter 21, Problem 75

When two protons fuse in a star, the product is ²H plus a positron. Write the nuclear equation for this process.

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Identify the reactants and products in the fusion process: two protons (¹H) fuse to form deuterium (²H) and a positron (e⁺).
Write the nuclear equation starting with the reactants on the left side: ¹H + ¹H.
On the right side of the equation, write the products: ²H and e⁺.
Ensure that the equation is balanced in terms of both mass number and charge. The mass number on both sides should be equal, and the charge should also be balanced.
Combine the reactants and products into a complete nuclear equation: ¹H + ¹H → ²H + e⁺.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Nuclear Fusion

Nuclear fusion is the process where two light atomic nuclei combine to form a heavier nucleus, releasing energy in the process. In stars, this occurs under extreme temperatures and pressures, allowing protons to overcome their electrostatic repulsion. The fusion of protons in stars is a fundamental reaction that powers stellar energy and leads to the formation of heavier elements.
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Nuclear Equations

Nuclear equations represent the transformation of atomic nuclei during nuclear reactions. They show the reactants and products, including changes in atomic numbers and mass numbers. In the case of proton fusion, the equation must balance the total number of protons and neutrons before and after the reaction, ensuring conservation of mass and charge.
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Positron Emission

A positron is the antimatter counterpart of an electron, possessing the same mass but a positive charge. In nuclear reactions, such as proton fusion, positron emission occurs when a proton is converted into a neutron, releasing a positron and a neutrino. This process is crucial in understanding particle interactions and the behavior of matter in high-energy environments like stars.
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Related Practice
Textbook Question

Chlorine has two stable nuclides, 35Cl and 37Cl. In contrast, 36Cl is a radioactive nuclide that decays by beta emission. (a) What is the product of decay of 36Cl?

Textbook Question

Chlorine has two stable nuclides, 35Cl and 37Cl. In contrast, 36Cl is a radioactive nuclide that decays by beta emission. (b) Based on the empirical rules about nuclear stability, explain why the nucleus of 36Cl is less stable than either 35Cl or 37Cl.

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 ?

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 (a) What are the identities of isotopes Q and Z? (c) Collision of ions of isotope Q with a target was also used to produce the first atoms of livermorium, Lv. The initial product of this collision was 296116Lv. What was the target isotope with which Q collided in this experiment?

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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