If atomic number 117,120 are discovered then their blocks will be

Options

A. s,p
B. p,s
C. p,d
D. d,p

Answer

To determine the blocks of the elements with atomic numbers 117 and 120, we need to analyze their electronic configurations step by step.

### Step 1: Identify the nearest noble gas
The nearest noble gas to atomic number 117 is radon (Rn), which has an atomic number of 86.

### Step 2: Write the electronic configuration for atomic number 117
Starting from radon (Rn), we add the electrons for atomic number 117:
- Radon (Rn): \( [Rn] = 86 \)
- Next, we fill the orbitals:
- \( 5f \) orbitals: fully filled with 14 electrons (5f14)
- \( 6d \) orbitals: fully filled with 10 electrons (6d10)
- \( 7s \) orbitals: fully filled with 2 electrons (7s2)
- \( 7p \) orbitals: has 5 electrons (7p5)

Thus, the electronic configuration of element 117 is:
\[ [Rn] 5f^{14} 6d^{10} 7s^{2} 7p^{5} \]

### Step 3: Determine the block for atomic number 117
Since the last electrons added are in the \( 7p \) orbital, element 117 belongs to the **p-block** of the periodic table.

### Step 4: Write the electronic configuration for atomic number 120
Now, for atomic number 120, we continue from the configuration of 117:
- The configuration remains the same up to this point:
- \( 5f^{14} \)
- \( 6d^{10} \)
- \( 7s^{2} \)
- For 120, we fill the \( 7p \) orbitals completely, which means:
- \( 7p \) orbitals will be fully filled with 6 electrons (7p6).

Thus, the electronic configuration of element 120 is:
\[ [Rn] 5f^{14} 6d^{10} 7s^{2} 7p^{6} \]

### Step 5: Determine the block for atomic number 120
Since the last electrons added are in the \( 7s \) orbital (after filling \( 7p \)), element 120 belongs to the **s-block** of the periodic table.

### Conclusion
- Atomic number 117 belongs to the **p-block**.
- Atomic number 120 belongs to the **s-block**.

### Final Answer
The blocks for atomic numbers 117 and 120 are **p-block** and **s-block**, respectively.

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