Task Overview

The periodic table is arranged so that elements with similar properties are found in the same column (Group). The row (Period) an element is in tells us how many electron shells it has. The outermost electrons, called valence electrons, are largely responsible for how an element reacts. In this simulation, you will observe the reactions of various metals with water and look for patterns in their reactivity.

Performance Expectations:

• HS-PS1-1: Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms.

Part 1: Exploring Group 1 (The Alkali Metals)

1. Open the Alkali Metals Phenomenon Simulation.
2. Drop Lithium (Li) into the water.
   • Observe the macroscopic reaction. What happens? How long does it last?
   • Look at the atomic model. How many total shells does Li have? How many valence electrons (red dots) are in the outermost shell?
   • Record the Peak Temperature and Reaction Time from the Sensor Readout.
3. Now, drop Sodium (Na) into the water.
   • How does the reaction compare to Lithium? (Is it faster/slower, more/less violent?)
   • Look at the atomic model. How many total shells does Na have? How many valence electrons?
   • Record the Peak Temperature and Reaction Time.
4. Finally, drop Potassium (K) into the water.
   • How does this reaction compare to Lithium and Sodium?
   • Look at the atomic model. How many total shells does K have? How many valence electrons?
   • Record the Peak Temperature and Reaction Time.

Analysis Question 1: Based on your observations of Li, Na, and K, what is the pattern in reactivity as you move down Group 1 of the periodic table?

Analysis Question 2: Look at the atomic models for Li, Na, and K. What structural feature do they all share? What structural feature changes as you move down the group, and how might this explain the trend in reactivity you observed?

Part 2: Exploring Across a Period

1. You have already observed Sodium (Na) in Period 3, Group 1.
2. Now drop Aluminum (Al) into the water. Aluminum is also in Period 3, but in Group 13.
   • Observe the macroscopic reaction. What happens?
   • Look at the atomic model. How many total shells does Al have? How many valence electrons?
   • Record the Peak Temperature and Reaction Time.

Analysis Question 3: Compare Sodium (Na) and Aluminum (Al). Both have their outermost electrons in the 3rd shell (Period 3). However, Na reacts violently, while Al has no noticeable reaction. How does the number of valence electrons differ between them, and how does this relate to their reactivity?

Part 3: The Mystery Metal

1. Click the button to drop the Mystery Metal (X) into the water.
   • Observe the macroscopic reaction carefully.
   • Look at the Sensor Readout to identify its Group and Period.
   • Look at its atomic model.

Analysis Question 4: Based on the reaction you observed (Peak Temperature, Reaction Time, and visual effects like sparks/flames), the Group number, and the number of valence electrons, what type of metal is Mystery Metal X? Where would it be located relative to Potassium (K) on the periodic table? Explain your reasoning using the patterns you discovered in Part 1.