Download Trends in Atomic Radii – Visualization Activity

Trends in Atomic Radii – Visualization Activity Name(s): Date: Class: Introduction: The reactivity of an atom depends on how easily the _____________________ electrons can be removed from or attracted to the atom, and that depends on their distance from the attractive force of the __________________. The further away electrons are from the nucleus, the ________________ easily they can be removed and the ___________________ reactive the metal element is. For nonmetals, the closer the electrons are to the nucleus the ____________________ its ability to attract more electrons and the ___________________ reactive the nonmetal element is. You will study the periodic trends in the atomic radii of the first main group elements (hydrogen through krypton) in this activity. Materials and Methods: ruler scissors 96‐well microplate straws periodic table 1. Each atomic radius (measured in picometers) has been converted to an enlarged scale in centimeters (each radius was been multiplied by 1 cm/40 pm) in the chart below. Color code the elements’ symbols as metal, metalloid and nonmetal in the chart below: Key: Metal = , Metalloid = , Nonmetal = Element Converted Element Converted Element Converted Element Converted symbols radius (cm) symbols radius symbols radius (cm) symbols radius (Period (Period 2) (cm) (Period (Period (cm) 1) 3) 4) H He 2.0 0.8 Li Be B C N O F Ne 3.9 2.8 2.1 1.9 1.8 1.5 1.7 1.8 Na Mg Al Si P S Cl Ar 4.6 4.0 3.6 3.0 2.7 2.6 2.3 2.5 K Ca Ga Ge As Se Br Kr 5.8 4.9 3.4 3.1 3.0 2.9 3.0 2.8 2. Cut straws to the lengths in the above chart to represent the relative atomic radii. Using a permanent marker, label each straw piece with the element symbol. 3. Place the straws into a 96‐well plate that will be oriented to correlate with a periodic table. Row A Period 1 Elements Row B Period 2 Elements Row C Period 3 Elements Row D Period 4 Elements Analysis: 1. How do the atomic radii change as you go from left to right across a period? 2. WHY do the atomic radii do this? 3. What happens to a metal’s ability to become an ion as you move across a period? 4. What happens to a nonmetal’s ability to become an ion as you move across a period? 5. How do the atomic radii change as you move from top to bottom within a group? 6. WHY do the atomic radii do this? 7. What happens to a metal’s ability to become an ion as you move down a group? 8. What happens to a nonmetal’s ability to become an ion as you move down a group? Conclusion: