Question

A Review Learning Goal: Part D To understand the notation and basic quantities involved in nuclear physics. Which of the following choices lists a pair of isotopes? Nuclear physics borrows the symbols for elements from chemistry. However, knowing which element we are dealing with only tells us one of the numbers important to nuclear physics. When referring to a specific nucleus, we use the following notation: O s Fe. C and !AN He and Li 5N and 160 H and H O Submit Request Answer The superscript, 56 in this case, denotes the total number of nucleons (protons and neutrons) in the nucleus. This is called the nucleon number and is given the symbol A. The subscript, 26 in this case, is the number of protons in the nucleus. This is called the atomic number and is given the symbol Z. An atom's atomic number determines which element the atom is, in this case Fe (iron). Another important number characterizing an atom is the neutron number N. Since A is the total number of nucleons in the nucleus, the neutron number may be found from the equation A= 2 + N. Solving for N gives N = A - Z. Nuclei with the same atomic number but different neutron numbers are called isotopes. Isotopes are often written in a form such as "iron-56." It has been found that the radii of most nuclei are well approximated by the equation R =R A %, where Ro = 1.2 x 10-15 m is an experimentally determined constant. Because the mass of a nucleon (a proton or a neutron) is close to one atomic mass unit (1 u), the nucleon number A is sometimes called the mass number. Part E

Answer 1

o soll. D 180 topex wil have: Same a fomie Number but different 'Wue leon Number © B Marpsvoore = VAR 4/35/Ro Ak? - ARREA a dei Je oy 4* )