Isotope Lab A

Isotope LabA Introduction & Purpose: This lab exercise is designed to show you isotopes of an element in a simulation form. You will be asked to gather data about the “isotopes” and organize the data. If atoms were as large as beans they could be sorted, counted, and massed. In this experiment we will sort, count, andmass three different kinds of beans and imagine that we are observing three different isotopes ofthe same element. The three different isotopes are blackium, brownium,and whitium. Finally we will calculate the isotopic mass, the isotopic abundance, and the atomicmass of the bean element. Definitions: ● Isotopic mass – the average mass of the atoms of a specific isotope of an element ● Isotopic abundance – what percent of the element’s atoms are a specific isotope ● Atomic mass – the average mass of an element’s atoms Materials:Plastic cup or ziplock bags of beans (black, brown, & white); electronic balance Procedure: 1. Obtain a plastic cup which contains many atoms (beans). 2. Sort the atoms (beans) into a group for each isotope: black, brown, white. Record the total number of atoms and the number of each type of isotope (blackium, brownium, and whitium) in the data table. 3. Determine the isotopic mass: a) find the total mass of each of the three isotope groups and record on data table b) find the average mass of a single atom of each isotope and record on the data table to the nearest 0.001g. EXAMPLE:I counted 340 white beans. They have a mass of 80 grams. The average mass of one white bean is 80 / 340 = 0.235 grams. 4. Find the isotopic abundance (% of beans) for each isotope by dividing the number of atoms of one isotope by the total number of atoms (black, brown, plus white) and multiplying by 100%. Record on the data table to the nearest 0.1%. EXAMPLE:There are a total of 500 atoms. 340 are white beans. Therefore, (340 ÷ 500) x 100% = 68.0% are white beans (whitium). 5. Determine the atomic mass for based on the isotopic abundances and the isotopic masses. FORMULA TO CALCULATE ATOMIC MASS = (blackium %) x (mass of one blackium atom) + (brownium %) x (mass of one brownium atom) + (whitium %) x (mass of one whitium atom) 6. Place all the beans back in the plastic cup or ziplock bag. Data: ● Show one sample of each calculation. Remember significant digits for all calculations. ● Complete the data table. DATA TABLE Isotope information: Total number of bean element atoms in cup = 345 13.00 ISOTOPE # OF BEANS (ATOMS) MASS OF BEANS (ATOMS) AVERAGE MASS OF 1 BEAN (GRAMS) % OF BEANS Blackium 170 36.10 3.52 2.01 Brownium 100 30.10 3.32 3.45 Whitium 75 21.75 3.45 4.6 Calculations for atomic mass of BEANIUM…(use the data table to complete) % of blackium x mass + % of brownium x mass + % of whitium xmass = Atomic mass “atoms” of blackium “atoms of brownium “atoms” of whitium of BEANIUM x g + x 72.45=blackium 103.84=brownium g + x 100.05=whitium g = g Conclusion Focus Questions(Note: Your conclusion should be a paragraph!): 1. Which pieces of your data must be measured and which can be calculated? - The mass of beans has to be measured. The average mass of 1 bean can be calculated because you have to divide. 2. Was the average mass of the beans a whole number or a decimal? Explain. - The average mass of the beans were decimals because we needed to be the most precise and accurate for the measurements to check out. 3. Explain any differences between the atomic mass of your BEANIUMsample and that of a different lab group. Explain why the difference would be smaller if larger samples were used. - The difference in the lab group's data was very small because everyone received the same amount but not every bean weighed the same. Using more beans will not really affect it just because the weight does not change as much. 4. What is an isotope? - Isotopes are irregularities of a particular chemical element that vary in neutron number. All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom. 5. What is the relationship between an element’s isotopes and the element’s atomic mass? - Because of each isotope of a given element has the same atomic number but different mass which makes up the protons and neutrons. 6. Explain how this lab simulates the various isotopes of an element. - Isotopes are molecules with a similar number of protons however that has an alternate number of neutrons. Since the nuclear number is equivalent to the number of protons and the nuclear mass is the entirety of protons and neutrons. What are at least two sources of error for this activity? (A source of error is an error that could have affected your results.) - Two sources of error for this activity is counting the number of beans wrong and us not being precise enough while trying to measure the weight of the beans which could lead to the problem being wrong. Conclusion: In this lab we used beans to demonstrate isotopes in a simulation form. We used brown, black and white beans to find the total mass of each of the three isotope groups and record on the data table. And we found the average mass of a single atom of each isotope. When we measured the beans we had to subtract the mass of the cup from the mass of the beans in order for it to be exact. For example, the mass of Blackium 36.10 and the average mass of 1 bean is 3.52. We came across some errors along the way because we were not 100% exact with counting the beans and that is where you can go wrong.Aisde from that, the lab was very succesful in finding all the information was that nesscary.