Assertion (A)Although Zn is the member of Ist series yet not a transition element.
Reason ( R) The orbitals in Zn are completely filled in ground as well as in oxidation state.

Options

A. Both Assertion and Reason are correct explanation of the Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion
C. Assertion is correct but Reason is incorrect
D. Both Assertion and Reason are incorrect

Answer

To analyze the assertion and reason provided in the question, let's break it down step by step.

### Step 1: Understanding the Assertion
The assertion states that "although Zn is a member of the 1st series, it is not a transition element."

**Explanation:**
Zinc (Zn) is indeed part of the first transition series, which includes elements from Scandium (Sc) to Copper (Cu). However, zinc is often excluded from the list of transition metals because it does not exhibit the typical properties associated with transition metals.

**Hint:** Remember that transition metals are defined by their ability to form variable oxidation states and to have partially filled d-orbitals.

### Step 2: Understanding the Reason
The reason given is "the orbitals in Zn are completely filled in the ground as well as in oxidation state."

**Explanation:**
In its ground state, zinc has the electron configuration of [Ar] 3d^10 4s^2. When zinc loses electrons to form its common oxidation state of +2, it loses the two 4s electrons, resulting in the configuration [Ar] 3d^10. In both states (ground state and oxidation state), the d-orbitals are completely filled (3d^10), which is a key characteristic that disqualifies it from being a transition metal.

**Hint:** Transition metals typically have partially filled d-orbitals, which allows them to exhibit variable oxidation states and form colored compounds.

### Step 3: Conclusion
Both the assertion and the reason are correct. The assertion correctly states that zinc is not a transition element despite being in the first series, and the reason accurately explains that the d-orbitals are completely filled in both the ground state and oxidation state.

### Final Answer
- **Assertion (A)**: True - Zinc is a member of the first series but is not considered a transition element.
- **Reason (R)**: True - The orbitals in Zn are completely filled in both ground and oxidation states.