Answer
(a) $^{17}_{8}$O
(b) $^{37}_{17}$Cl
(c) $^{60}_{27}$Co
(d) $^{57}_{26}$Fe
(e) $^{131}_{53}$I
(f) $^{7}_{3}$Li
Work Step by Step
(a) We know that Z is the atomic number, so a Z = 8 indicates that this is an isotope of oxygen. The Z value is written as a subscript to the left of the element symbol. We also need the A value, which is the mass number. The mass number is the sum of the number of protons and neutrons in the atom. If the number of protons is given by the Z number and the number of neutrons is given as 9, we can add these two values to get a mass number of 17. The atomic symbol of this isotope is $^{17}_{8}$O.
(b) We know that the A value is the mass number. The mass number is the sum of the number of protons and neutrons in the atom. If we are given that the element we are working with is chlorine, then we know that its atomic number is 17, which is the value for Z. Now we have both the A value and the Z value, we write the A value as a superscript to the left of the element symbol and the Z value as a subscript of the element symbol. Therefore, the atomic symbol for this isotope is $^{37}_{17}$Cl.
(c) We know that Z is the atomic number, so a Z = 27 indicates that this is an isotope of cobalt. The Z value is written as a subscript to the left of the element symbol. We also need the A value, which is the mass number. The mass number is the sum of the number of protons and neutrons in the atom. We are given the A value as 60. This will be written as a superscript to the left of the element symbol. The atomic symbol for this isotope is $^{60}_{27}$Co.
(d) We know that the number of protons for this element is 26, which is also the Z value. A Z value of 26 means that this is an isotope of iron. We are given the number of neutrons, which is 31. The A value is the number of protons added to the number of neutrons. So if we add 26 protons to 31 neutrons, we get an A value of 57. We write the A value as a superscript to the left of the element symbol and the Z value as a subscript also to the left of the element symbol. Therefore, the atomic symbol for this isotope is $^{57}_{26}$Fe.
(e) We know that the mass number is the sum of the number of protons and neutrons in an atom; this is the value of A. If we are given that the element we are working with is I, the element symbol for iodine, then we know that its atomic number is 53, which is the value for Z. Now we have both the A value and the Z value, so we write the A value as a superscript to the left of the element symbol and the Z value as a subscript to the left of the element symbol. Therefore, the atomic symbol for this isotope is $^{131}_{53}$I.
(f) We know that Z is the atomic number, so a Z = 3 indicates that this is an isotope of lithium. The Z value is written as a subscript to the left of the element symbol. We also need the A value, which is the mass number. The mass number is the sum of the number of protons and neutrons in the atom. If the number of protons is given by the Z number (3) and the number of neutrons is given as 4, we can add these two values to get a mass number of 7. Therefore, the atomic symbol of this isotope is $^{7}_{3}$Li.
