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Slide 2 / 13 Beanium Lab The goals of this lab are to: · Introduce the concept of naturally occurring isotopes. · Determine the average atomic mass of a new element using the relative masses and relative abundances of the isotopes. · Differentiate between an average and a weighted average. · Understand why it is important to use a weighted average to determine the average atomic mass of an element.
Slide 3 / 13 Materials: Three or four samples of different beans, balance, pencil, laboratory record sheet and weighing dishes if available. Setup: · Each student group is given a random assortment of the three or four beans that represents the element Beanium. · Each team needs access to a balance to weigh their isotopes and to a calculator to complete their calculations.
Slide 4 / 13 Guided Lab - Procedure and Examples
Slide 5 / 13 Roles Lab teams should consist of 3-4 members. The teams will take turns using the available balances. 1. One person counts and masses the isotopes. 2. One person (Collector) records the data. 3. One or two people (Statistician) will complete the calculations.
Slide 6 / 13 Procedure Separate your Beanium sample into its different isotopes. · Count the number of each isotope and record this information on · your data table. Mass each group of isotopes together and record this information on · your data table. Follow the steps outlined in the Analysis section of your lab sheet to · complete your calculations. Record your data.
Slide 7 / 13 Safety Warning: Be aware that it is not safe to ingest the beans, this could be a choking hazard. Also be sure to return all beans to your teacher to avoid any slips or falls.
Slide 8 / 13 Data Collection If a triple beam balance is being used · be sure to mass your isotopes to hundredth place, the last digit is an estimate and is significant. If an electronic balance is used mass to · the limitations of the balance.
Slide 9 / 13 Analysis and Application Questions
Slide 10 / 13 1 What would be your estimate of the average atomic mass of the element described below? Relative Isotope Atomic Mass Abundance 88 Tp .0209 87.998 90 Tp .1001 90.001 92 Tp .8790 91.998 A 88 B 90 C 92 D 89
Slide 11 / 13 2 What is the average atomic mass of the element described below? Relative Isotope Atomic Mass Abundance 88 Tp .0209 87.998 90 Tp .1001 90.001 92 Tp .8790 91.998
Slide 12 / 13 3 It is always better to use a weighted average to determine the average atomic mass of an element. True False
Slide 13 / 13
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