The elements with atomic number 117 and 120 are yet to be discovered. In which group would you plac these elements when discovered?

Options

A. 17, 2
B. 17,4
C. 15,3
D. 18,2

Answer

To determine the groups for the undiscovered elements with atomic numbers 117 and 120, we can follow these steps:

### Step 1: Identify the Periodic Table Structure
The periodic table is organized into blocks:
- **S-block**: Groups 1 and 2
- **P-block**: Groups 13 to 18
- **D-block**: Transition metals, Groups 3 to 12
- **F-block**: Lanthanides and actinides

### Step 2: Locate the Last Known Element
The last known element is Oganesson (Og) with atomic number 118, which is in the **P-block** and belongs to **Group 18** (the noble gases).

### Step 3: Determine the Group for Atomic Number 117
Since Group 18 is occupied by Oganesson (118), the element with atomic number 117 would be the one just before it in the P-block. Therefore, it would belong to **Group 17** (the halogens).

### Step 4: Determine the Group for Atomic Number 120
After Oganesson (118), the next elements would follow the order of filling the periodic table. Atomic number 119 would be in the **S-block** (Group 1), and thus atomic number 120 would be in the **S-block** as well, specifically in **Group 2** (the alkaline earth metals).

### Conclusion
- Element with atomic number 117 would belong to **Group 17**.
- Element with atomic number 120 would belong to **Group 2**.

### Final Answer
- Atomic number 117: Group 17
- Atomic number 120: Group 2

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