Nuclear Equations Quiz

PDF page 1145: Changes of nuclei that result in changes in their atomic numbers, mass numbers, or energy states are nuclear reactions. To describe a nuclear reaction, we use an equation that identifies the nuclides involved in the reaction, their mass numbers and atomic numbers, and the other particles involved in the reaction.

PDF page 1145: β, also represented He, also represented by the symbol α are high-energy helium nuclei. Beta particles

PDF page 1145: by the symbol e are high-energy electrons, and gamma rays are photons of very high-energy electromagnetic

PDF page 1145: The subscripts and superscripts are necessary for balancing nuclear equations, but are usually optional in other circumstances. For example, an alpha particle is a helium nucleus (He) with a charge of +2 and a mass number of 4, 4 so it is symbolized He. This works because, in general, the ion charge is not important in the balancing of nuclear 2 equations.

PDF page 1146: Note that positrons are exactly like electrons, except they have the opposite charge. They are the most common example of antimatter, particles with the same mass but the opposite state of another property (for example, charge) than ordinary matter. When antimatter encounters ordinary matter, both are annihilated and their mass is converted into energy in the form of gamma rays (γ)—and other much smaller subnuclear particles, which are beyond the

PDF page 1146: scope of this chapter—according to the mass-energy equivalence equation E = mc , seen in the preceding section. For example, when a positron and an electron collide, both are annihilated and two gamma ray photons are created: 0 0 e + e ⟶ γ + γ −1 +1 As seen in the chapter discussing light and electromagnetic radiation, gamma rays compose short wavelength, highenergy electromagnetic radiation and are (much) more energetic than better-known X-rays that can behave as particles in the wave-particle duality sense. Gamma rays are a type of high energy electromagnetic radiation produced when a nucleus undergoes a transition from a higher to a lower energy state, similar to how a photon is produced by an electronic transition from a higher to a lower energy level. Due to the much larger energy differences between nuclear energy shells, gamma rays emanating from a nucleus have energies that are typically millions of times larger than electromagnetic radiation emanating from electronic transitions.

PDF page 1146: scope of this chapter—according to the mass-energy equivalence equation E = mc , seen in the preceding section. For example, when a positron and an electron collide, both are annihilated and two gamma ray photons are created: 0 0 e + e ⟶ γ + γ −1 +1 As seen in the chapter discussing light and electromagnetic radiation, gamma rays compose short wavelength, highenergy electromagnetic radiation and are (much) more energetic than better-known X-rays that can behave as particles in the wave-particle duality sense. Gamma rays are a type of high energy electromagnetic radiation produced when a nucleus undergoes a transition from a higher to a lower energy state, similar to how a photon is produced by an electronic transition from a higher to a lower energy level. Due to the much larger energy differences between nuclear energy shells, gamma rays emanating from a nucleus have energies that are typically millions of times larger than electromagnetic radiation emanating from electronic transitions.

PDF page 1146: A balanced chemical reaction equation reflects the fact that during a chemical reaction, bonds break and form, and atoms are rearranged, but the total numbers of atoms of each element are conserved and do not change. A balanced nuclear reaction equation indicates that there is a rearrangement during a nuclear reaction, but of nucleons (subatomic particles within the atoms’ nuclei) rather than atoms. Nuclear reactions also follow conservation laws, and they are balanced in two ways:

PDF page 1146: A balanced chemical reaction equation reflects the fact that during a chemical reaction, bonds break and form, and atoms are rearranged, but the total numbers of atoms of each element are conserved and do not change. A balanced nuclear reaction equation indicates that there is a rearrangement during a nuclear reaction, but of nucleons (subatomic particles within the atoms’ nuclei) rather than atoms. Nuclear reactions also follow conservation laws, and they are balanced in two ways:

PDF page 1147: 25 + 4 = A + 1, or A = 28

PDF page 1147: 12 + 2 = Z + 1, and Z = 13

PDF page 1147: 25 The reaction of an α particle with magnesium-25 ( Mg) produces a proton and a nuclide of another 12 element. Identify the new nuclide produced. Solution The nuclear reaction can be written as: 25 4 1 A Mg + He ⟶ H + X Z 12 2 1 where A is the mass number and Z is the atomic number of the new nuclide, X. Because the sum of the mass numbers of the reactants must equal the sum of the mass numbers of the products:

PDF page 1147: 25 + 4 = A + 1, or A = 28

PDF page 1147: 12 + 2 = Z + 1, and Z = 13

PDF page 1147: 28 Check the periodic table: The element with nuclear charge = +13 is aluminum. Thus, the product is Al. 13

PDF page 1147: scientist Marie Curie and her husband Pierre in 1898. It decays, emitting α particles: 208 212 4 Po ⟶ Pb + He 84 82 2 17