1.2 Mass Spectroscopy of Elements

8. Based on the information shown above, (a) calculate the average atomic mass of the element. (b) What is the most likely identity of this element? 10. A certain element has two naturally occurring isotopes with mass numbers of 63 and 65. (a) What is the most likely identity of this element? (b) Fill in the table below. Mass Number Protons Neutrons 63 65 (c) Which isotope of this element, mass number = 63 or mass number = 65, is more abundant in nature? Justify your answer. 11. If an element has several naturally occurring isotopes, the calculation of the average atomic mass of the element can be a bit more complicated. Mass Number Abundance 154 2.18% 155 14.80% 156 20.47% 157 15.65% 158 24.84% 160 22.06% (a) Based on the information above, estimate the average atomic mass of the element to the nearest whole number. Then use a calculator to determine the average atomic mass. (b) What is the most likely identity of this element?