Nuclear bombardment reactions

The nuclear reactions discussed in the previous section are radioactive decay reactions, in which a nucleus spontaneously decays to another nucleus and emits a particle, such as an alpha or beta particle. In 1919, Ernest Rutherford discovered that it is 

Some of the uses of radioactive isotopes are discussed in Section 21.5. 

Rutherford used a radioactive element as a source of alpha particles and allowed these particles to collide with nitrogen nuclei. He discovered that protons are ejected in the process. The equation for the nuclear reaction is 

The experiments were repeated on other hght nuclei, most of which were transmuted to other elements with the ejection of a proton. These experiments yielded two significant results. First, they strengthened the view that all nuclei contain protons. Second, they showed for the first time that it is possible to change one element into another under laboratory control. 

When beryllium is bombarded with alpha particles, a penetrating radiation is given off that is not deflected by electric or magnetic fields. Therefore, the radiation does not consist of charged particles. The British physicist James Chadwick (1891—1974) suggested in 1932 that the radiation from beryllium consists of neutral particles, each with a mass approximately that of a proton. The particles are called neutrons. The reaction that resulted in the discovery of the neutron is 

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Nuclear bombardment reactions in which the product is radioactive constitute the basis of radioactivation analysis (p. 456). Although in principle any bombardment-decay sequence may be used the analyst is largely concerned with thermal neutron activation. Equation (10.13) relates the induced activity to the amount of the parent nucleide (analyte). However, practical difficulties arise because of flux inhomogeneities. It is common therefore to irradiate a standard with very similar characteristics alongside the sample, e.g. for a silicate rock sample a standard solution would be evaporated on to a similar amount of pure silica. On the assumption that identical specific activities for the analyte are then induced in the sample and standard, the amount w2 of analyte is readily calculated from... 

As was the case for the previously discovered transuranium elements, element 97 was first produced via a nuclear bombardment reaction. In December, 1949, ion-exchange separation of the products... 

What are nuclear bombardment reactions Explain the shorthand notation used to describe bombardment reactions. 

Fill in the missing symbols in the foUowLng nuclear bombardment reactions. 

The second type of nuclear reaction is a nuclear bombardment reaction, a nuclear reaction in which a nucleus is bombarded, or struck, by another nucleus or by a nuclear particle. If there is sufficient energy in this collision, the nuclear particles of the reactants rearrange to give a product nucleus or nuclei. First, we will look at radioactive decay. 

In 1933, a nuclear bombardment reaction was used to produce the first artificial radioactive isotope. Irene and Frederic Joliot-Curie found that aluminum bombarded with alpha particles produces phosphorus-30, which decays by enutting positrons. The... 

Nuclear bombardment reactions are often referred to by an abbreviated notation. For example, the reaction... 

Determining the Product Nucleus in a Nuclear Bombardment Reaction... 

Using the notation for a bombardment reaction Given an equation for a nuclear bombardment reaction, write the abbreviated notation, or vice versa. (EXAMPLE 21.5)... 

Nuclear bombardment reaction a nuclear reaction in which a nucleus is bombarded, or struck, by another nucleus or by a nuclear particle, (p. 855)... 

Nuclear Bombardment and Induced Radioactivity COAL 9 Define or identify nuclear bombardment reactions. COAL 10 Distinguish natural radioactivity from induced radioactivity produced by bombardment reactions. 

As was the case for the previously discovered transuranium elements, element 97 was first produced via a nuclear bombardment reaction. In December 1949 ion-exchange separation of the products formed by the bombardment of Am with accelerated alpha particles provided a new electron-capture activity eluting just ahead of curium [1,2]. This activity was assigned to an isotope (mass number 243) of element 97. The new element was named berkelium after Berkeley, California, the city of its discovery, in a parallel manner to the naming of its lanthanide analog, terbium, after Ytterby, Sweden. The initial investigations of the chemical properties of berkelium were limited to tracer experiments (ion exchange and co-precipitation), but these were sufficient to establish the stability of Bk(iii) and the accessibility of Bk(iv) in aqueous solution and to estimate the electrochemical potential of the Bk(iv)/Bk(iii) couple [2,3]. 

EXAMPLE 25-2 Writing Equations for Nuclear Bombardment Reactions... 

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