Write the electronic configuration of the element having atomic number `56`

Answer

To find the electronic configuration of the element with atomic number 56, follow these steps:

### Step 1: Identify the Element
The atomic number 56 corresponds to the element Barium (Ba).

### Step 2: Understand the Aufbau Principle
The Aufbau principle states that electrons fill atomic orbitals in order of increasing energy levels. The order of filling is generally:
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p.

### Step 3: Fill the Orbitals
We will fill the orbitals according to the Aufbau principle until we reach 56 electrons:
- 1s² (2 electrons)
- 2s² (2 electrons)
- 2p⁶ (6 electrons)
- 3s² (2 electrons)
- 3p⁶ (6 electrons)
- 4s² (2 electrons)
- 3d¹⁰ (10 electrons)
- 4p⁶ (6 electrons)
- 5s² (2 electrons)
- 4d¹⁰ (10 electrons)
- 5p⁶ (6 electrons)
- 6s² (2 electrons)

### Step 4: Count the Electrons
Now, let's count the total number of electrons filled:
- 2 (1s) + 2 (2s) + 6 (2p) + 2 (3s) + 6 (3p) + 2 (4s) + 10 (3d) + 6 (4p) + 2 (5s) + 10 (4d) + 6 (5p) + 2 (6s) = 56 electrons.

### Step 5: Write the Final Electronic Configuration
The electronic configuration for Barium (Ba) with atomic number 56 is:
\[ \text{1s}^2 \, \text{2s}^2 \, \text{2p}^6 \, \text{3s}^2 \, \text{3p}^6 \, \text{4s}^2 \, \text{3d}^{10} \, \text{4p}^6 \, \text{5s}^2 \, \text{4d}^{10} \, \text{5p}^6 \, \text{6s}^2 \]

### Summary
The electronic configuration of the element with atomic number 56 (Barium) is:
\[ \text{[Xe]} \, \text{6s}^2 \]
or explicitly:
\[ \text{1s}^2 \, \text{2s}^2 \, \text{2p}^6 \, \text{3s}^2 \, \text{3p}^6 \, \text{4s}^2 \, \text{3d}^{10} \, \text{4p}^6 \, \text{5s}^2 \, \text{4d}^{10} \, \text{5p}^6 \, \text{6s}^2 \]