Problem 103 - Chemistry The Central Science

Question

Scientists have speculated that element 126 might have a moderate stability, allowing it to be synthesized and characterized. Predict what the condensed electron configuration of this element might be.

Step-by-Step Solution

Answer

The predicted condensed electron configuration for element 126 is \[ \text{Rn} \ 7s^2 \ 5f^14 \ 6d^10 \ 7p^14. \]

Step 1: Identify the Previous Noble Gas

Before we can start building the electron configuration, we need to determine which noble gas element comes before element 126 in the periodic table. This will be the starting point for our electron configuration. The last noble gas with a lower atomic number than 126 is Radon (Rn), which has atomic number 86. So our starting point will be Rn.

Step 2: Build the Electron Configuration

Starting with Rn as our base, we will add electrons one at a time, following the Aufbau principle. This principle states that electrons are added to orbitals of lower energy first, then orbitals of higher energy.

Step 2.1: Add Electrons to the 7s Orbital

After Rn, the next lowest energy orbital is the 7s orbital. A maximum of two electrons can occupy an s orbital. Thus, we add two electrons to the 7s orbital: Rn 7s^2

Step 2.2: Add Electrons to the 5f Orbital

The 5f orbital has a capacity for 14 electrons. After filling the 7s orbital, we add 14 electrons to the 5f orbital: Rn 7s^2 5f^14

Step 2.3: Add Electrons to the 6d Orbital

Moving on to the 6d orbital, it has a capacity for 10 electrons. We add 10 electrons to the 6d orbital: Rn 7s^2 5f^14 6d^10

Step 2.4: Add Electrons to the 7p Orbital

Finally, we reach the 7p orbital. Up to this point, we have already assigned (86 + 2 + 14 + 10) = 112 electrons. Since element 126 has 126 electrons, we need to add 14 more electrons to complete its electron configuration: Rn 7s^2 5f^14 6d^10 7p^14 In conclusion, the predicted condensed electron configuration for element 126 is \[ \text{Rn} \ 7s^2 \ 5f^14 \ 6d^10 \ 7p^14. \]