Goal:

To investigate isotopes of the element ‘beanium’. Calculating the average masses, relative abundances, and atomic mass of beanium.

  1. Obtain a sample of the fictitious element beanium containing:

Blue beans, green beans and orange beans

SCH3U / Investigation 2: Beanium
Matter, Trends & Bonding
  1. Separate the isotopes (Blue beans, green beans and orange beans) of the beanium into three small beakers.
  1. Record the mass of the separate isotopes of all the Blue beans, green beans and orange beans
  1. Record on the DATA SHEET the mass of each isotope. Always record the proper precision of the analytical balance and the correct units.
  1. Count all the isotopes (Blue beans, green beans and orange beans).Record on the DATA SHEET as the amount of each isotope.
  1. Divide the mass of each isotope (Blue beans, green beans and orange beans)by the amount of each isotope to get the average mass of each isotope.Record on the DATA SHEET.
  1. Divide the amount of each isotope (Blue beans, green beans and orange beans) by the total number of all the isotopes to get the relative abundance of each isotope.Record on the DATA SHEET.
  1. Multiply the relative abundance by the average mass of each isotope to get the relative mass of each isotope.Record on the DATA SHEET.
  1. Multiply the relative abundance of each isotope by 100 to get the percent abundance of each isotope.Record on the DATA SHEET as percent abundance of isotope.
  1. Calculate the average atomic mass of the fictitious element beanium.Record on the DATA SHEET as average atomic mass of beanium.ave atomic mass = rel. mass isotope (blue) + rel. mass isotope (green) + rel. mass isotope (orange)

Data Sheet [A]

Blue / Green / Orange / Total
  1. Mass of each isotope

  1. Amount of each isotope

  1. Average mass of each isotope

  1. Relative abundance of each isotope

  1. Relative mass of each isotope

  1. Percent abundance of each isotope

  1. Average atomic mass of the fictitious element beanium =

Questions.

  1. What is atomic mass? [K]
  1. What is isotopic abundance? [K]
  1. Bromine has two naturally occurring isotopes. Bromine-79 has a mass of 78.918 amu and is 50.69% abundant. Using the atomic mass reported on the periodic table, determine the mass of bromine-81, the other isotope of bromine. [I]
  1. Antimony has two naturally occurring isotopes. The mass of antimony-121 is 120.904 amu and the mass of antimony-123 is 122.904 amu. Using the average mass from the periodic table, find the abundance of each isotope. (Remember that the sum of the two abundances must be 100) [I]