Part I: Atomic Radius and Ionization Energy



Name: _____________________________________________Date: __________________________ Mods: ______________Simulation: Periodic TrendsBackground: In this investigation you will examine several periodic trends, including atomic radius, ionization energy and electronegativity. You will be asked to interact with select atoms as you investigate these concepts.Part I: Atomic Radius and Ionization EnergyAnswer the following Pre-Activity Questions:Draw a picture to support a written definition of the word “radius”Assuming atoms are shaped like spheres, what subatomic particles would be found in the center? What subatomic particles would be found around the perimeter?Keeping in mind your answers to questions 1 & 2, in your own words describe the meaning of “atomic radius.”What is an ion? What is a valence electron? How is an ion formed?What do you think ionization energy means? Think about this in relation to your answer to question #4. **Check your answers with your teacher before moving on to the next portion of the activity.**Procedure: Using your chromebook, navigate to the website: RadiusChoose any element show in green from group 1 on the periodic table clicking on the element symbol. You should see details about the element that you chose appear at the bottom of the screen. Select another element from group 1 click on its symbol. Write the symbols and atomic number for each of the elements that you chose below:Which element appears larger in the side-by-side comparison?What is the value in picometers (pm) for the radius of each atom? Do these values support your answer from part b?Reset the selected data using the reset symbol . Next, choose an element from a different green group by clicking on its symbol. Again, choose a second element to compare from the same group. Write the symbols and atomic number for each of the elements that you chose below:Which element appears larger in the side-by-side comparison?What is the value in picometers (pm) for the radius of each atom? Do these values support your answer for part e?Based on your answer in question 1 parts a-f, what is the general trend in the atomic radius of atoms within the same group? Give suggestions for why you think this trend exists based on your interaction with the elements.Choose any element from period (row) 2 on the periodic table by clicking on the element symbol. You should see details about the element that you chose appear at the bottom of the screen.Select another element from period 2 by clicking on its symbol. Write the symbols and atomic number for each of the elements that you chose below:Which element appears larger in the side-by-side comparison?What is the value in picometers (pm) for the radius of each atom? Do these values support your answer for part b?Do your answer in part b & c surprise you? Explain.Reset the selected data using the reset symbol . Choose an element from a different period by clicking on its symbol. Again choose a second element to compare from the same period. Write the symbols and atomic number for each of the elements that you chose below:Which element appears larger in the side-by-side comparison?What is the value in picometers (pm) for the radius of each atom? Do these values support your answer for part e?Based on your answers in questions 2 parts a-g, what is the general trend in the atomic radius of atoms within the same period?Think about the possible contributing factors to the atomic radius trend within a period, specficially considering the protons in the nucleus, the electrons and the electron shells. List them below:Based on what you have learned, and without the assistance of the periodic trends simulation, predict which element is larger in the following pairs of atoms:a. Be or Src. Rb or Se. Br or Cab. P or Ard. F or Hef. Xe or Ba**Using the simulation, check your predicted answers to see if you are correct!**Ionization EnergyChoose an element from the Alkali Metal family (group 1) by clicking on the element symbol. You should see details about the element that you chose appear at the bottom of the screen.Using your cursor attempt to ionize the atom that you chose by pullin a valence electron from the electron shell. Describe what happened. (Were you successful? Was it “easy” to remove the electron? Did the atom seem to have a strong hold on the electron?)What was the ionization energy value for the atom that you chose? Write a definition for ionization energy.Did any other information about the atom change after you attempt to ionize the atom?Do NOT reset. Now choose the Noble Gas element that is in the same period as the Alkali metal chosen in part a. Attempt to ionize this atom by pulling a valence electron from the electron shell. Describe what happened. (Were you successful? Was it “easy” to remove the electron? Did the atom seem to have a strong hold on the electron?)What was the ionization energy value for the noble gas atom that you chose?Make a comparison statement about the two elements that you interacted with in terms of why they require different amounts of ionization energy.Next, with the two elements still selected click on the “Go to Graphs” button at the bottom. A graph should appear, you will need to ensure the “First Ionization Energy – (element)” filter is selected in the top right hand location of the graph. What trend in ionization energy do you observe for elements in the same period based on the data in the graph?While still analyzing the graph, make a prediction about the trend in ionization energy between atoms in the same period on the periodic table. For example, do atoms with larger atomic numbers have greater ionization energy than atoms with small atomic numbers in the same period?While still analyzing the graph, make a prediction about the trend in ionization energy between atoms in the same group on the periodic table. For example, do atoms with larger atomic numbers have greater ionization energy than atoms with small atomic numbers in the same group?Navigate back to the main page, and reset the data using the reset symbol . Now choose two elements that are in the same group. How do their ionization energy values compare? Does this data support your prediction from part h?Based on what you have learned, and without the assistance of the periodic trends simulation, organize the following lists of atoms from lowest ionization energy to highest ionization energy:S, Na, Al, ArI, F, Br, ClRb, O, Si, Mg, He**Use the simulation, check your predicted answer to see if you are correct!**Reflecting on what you have learned about both atomic radius and ionization energy at this point, which of the following statements best describe these trends? Circle ONE and explain below.Atoms that have large atomic radii also have large values of ionization energy.Atoms that have small atomic radii will have large values of ionization energy.Explain your choice referencing BOTH the atomic model and subatomic particles:Part II: ElectronegativityBackground: In this investigation you will examine the electronegativity of select atoms from the periodic table. NOTE: This simulation uses the phrase “Electron Affinity” instead of “Electronegativity”. For our purposes, these terms are the same.What subatomic particles are located in the nucleus of an atom? Does the nucleus of the atom have a charge? If so, what is it?What factors determine the size (radius of an atom? Explain.Draw a Bohr model for Magnesium (Mg) and Chlorine (Cl). Which atom should be larger?Is it more difficult to remove a valence electron from Magnesium (Mg) atom or a Chlorine (Cl) atom? Explain.What does a positively charged ion indicate in terms of its subatomic particles? Use the Calcium (Ca+2) as a specific example in your explanation.What does a negatively charged ion indicate in terms of its subatomic particles? Use the Fluoride ion (F-1) as a specific example in your explanation.**Check your answers with your teacher before moving on to the next portion of the activity.**Procedure: Reminder, “electron affinity” and “electronegativity” are the same. Using your chromebook, navigate to the website: any element shown in green from group 7 on the periodic table by clicking on the element symbol. You should see details about the element that you chose appear at the bottom of the screen.How many valence electrons are present in this atom?How can this atom become stable?Attempt to add an electron to the atom. Describe what happened:Comparing the neutral atom and its anion, what do you notice about the radius in the side-by-side comparison? Do the data values support the visual representation?Are there any other noticeable differences between the neutral atom and its anion (other than size)? List them below:Explain why there is a difference in size between the neutral atom and its anion, making specific reference to subatomic particles.Reset the selected data using the reset symbol . Choose any element shown in green from group 1 on the periodic table by clicking on the element symbol. You should see details about the element that you chose appear at the bottom of the screen.How many valence electrons are present in this atom?How can this atom become stable?Attempt to add an electron to the atom. Describe what happened:Why did this atom behave differently than the atom chosen in question 1?Reset the selected data using the reset symbol . Choose one of the following elements by clicking on the element symbol (O, P, S). You should see detail about the element that you chose appear at the bottom of the screen.How many valence electrons are present in this atom?How can this atom become stable?Attempt to stabilize the atom by adding the necessary number of electrons. Describe what happened:Comparing the neutral atom and its anion, what do you notice about the radius in the side-by-side comparison? Do that data values support the visual representation?Are there any other noticeable differences between the neutral atom and its anion (other than size)? List them below:Explain why there is a difference in size between the neutral atom and its anion, making specific reference to subatomic particles.Decide whether the following statements are true or false, and briefly explain your choice in the space provided after each statement.Metals usually have stronger electronegativity than non-metals.Noble gas elements have a very large value for electronegativity.The value for electronegativity is a negative value because when an electron is added to the outer shell of an atom, energy is released.Electronegativity values generally increase from left to right in a period on the periodic table.A larger numerical value for electronegativity means it is more difficult for an electron to be added to an atom.Define electronegativity using your own words. ................
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