If IUPAC name of an element is "unununium" then correct statement regarding element is:

Explanation

To solve the question regarding the element with the IUPAC name "unununium," we need to analyze the information provided step by step.

### Step-by-Step Solution:

1. **Identify the Atomic Number**:
- The IUPAC name "unununium" corresponds to the prefix "un" which means one. Since it is repeated three times, it indicates that the atomic number is 111.
- Therefore, the atomic number of unununium is **111**.

**Hint**: Remember that "un" means one, and the repetition indicates the number of digits in the atomic number.

2. **Determine the Electronic Configuration**:
- The electronic configuration for an element with atomic number 111 can be derived as follows:
- The configuration follows the order of filling orbitals:
- 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d¹⁰ 7p⁶ 7s¹
- Thus, the electronic configuration is **[Rn] 5f¹⁴ 6d¹⁰ 7s¹**.

**Hint**: Use the Aufbau principle to fill the orbitals in order of increasing energy levels.

3. **Determine the Period**:
- The period number of an element corresponds to the highest principal quantum number (n) in its electronic configuration.
- In this case, the outermost shell has n = 7, which means unununium is in **period 7**.

**Hint**: The period number is determined by the highest principal quantum number in the electron configuration.

4. **Determine the Group**:
- For transition metals, the group number can be calculated by adding the number of electrons in the outermost s orbital and the d subshell.
- For unununium:
- s orbital: 1 electron (7s¹)
- d orbital: 10 electrons (6d¹⁰)
- Group number = 1 (from s) + 10 (from d) = **Group 11**.

**Hint**: Transition metals are characterized by their d electrons, and the group number can be calculated based on s and d electrons.

5. **Classify the Element**:
- Since unununium has 10 electrons in its d subshell, it is classified as a **transition element**.

**Hint**: Transition elements are defined by having partially filled d orbitals.

### Conclusion:
Based on the analysis, the correct statement regarding the element "unununium" is that it is a **transition element** belonging to **period 7** and **group 11**.

### Final Answer:
The correct statement regarding the element unununium is that it is a **transition element**.