Isotope Models #1
1. Observe the 5 samples lettered A-­E. 2. Record your observations in the circles below. Sample A
Sample B
Sample C
Sample D
Sample E
Atomic #: Atomic #: Atomic #: Atomic #: Atomic #: Atomic Mass: Atomic Mass: Atomic Mass: Atomic Mass: Atomic Mass: Element: Element: Element: Element: Element: Isotope Notation Isotope Notation Isotope Notation Isotope Notation Isotope Notation Analysis:
1. How many ​different elements​ do you have samples of? How do you know? 2. What is different about the nucleus of each ​element​ sample? 3. This model is meant to help you determine what and ​isotope​ is. Use your model to create a definition of isotope. 4. ​ Isotope notation​: Use the sample to write the isotope notation for each of your samples. Chromium-58
Chromium-63
Sodium-12
Sodium-20
# of protons
# of neutrons
# of electrons
# of protons
# of neutrons
# of electrons
Iodine-
Iodine-
# of protons
# of neutrons
32
35
# of electrons
-22
-25
# of protons
# of neutrons
# of electrons
11
What do you see in this picture?
Isotope Model #2
Using a Model to Understand Variations in the Mass of Element Atoms You have received a sample of twelve Eggium atoms. Weigh each Eggium atom to find its mass. You can weigh the atoms in any order as long as you only weigh each atom once. Record the mass of each Eggium atom. Data Table
Frequency of Mass Occurrence Atom 12 Mass (g) 1 11 2 10 3 9 4 8 5 7 6 6 7 5 8 4 9 3 10 2 11 1 12 9 10 Mass 1 2 3 4 5 6 7 8 Find the following: Mean Mass of Eggium Mode Mass of Eggium Weighted Average Mass of Eggium Thinking about the nucleus of an atom, what do all Eggium atoms have in common? What could explain the variation in Eggium atomic mass numbers? Why do elements of the periodic table have decimal values for atomic weights? The ​mean​ is an mathematical average. Find the sum of the masses and divide by 12 to find the mean. Create a ​histogram​ that shows how frequently a mass occurs in the sample. You will need to add labels to the X-­axis of the graph. Count the occurrence of mass. Shade in the number of boxes that corresponds to the occurrence count. The​ mode​ is the most frequently occurring value, in this case the most frequently occurring mass. Percentage​ is a ratio expressed as a fraction of 100. A ​weighted average​ results from ​from the multiplication of each component by a factor reflecting its occurrence.