To determine which set of elements among the given options are called non-transition elements, we need to analyze the electronic configurations of each set. Here’s a step-by-step solution:
### Step 1: Understand the definition of transition elements
Transition elements are defined as those elements that have partially filled d orbitals in their elemental or common oxidation states. Their electronic configuration typically follows the pattern of (n-1)d^1 to (n-1)d^10 and ns^1 to ns^2.
### Step 2: Analyze the first set of elements: Cu, Ag, Au
- **Copper (Cu)**: Electronic configuration is [Ar] 3d^10 4s^1
- **Silver (Ag)**: Electronic configuration is [Kr] 4d^10 5s^1
- **Gold (Au)**: Electronic configuration is [Xe] 4f^14 5d^10 6s^1
All three elements have partially filled d orbitals (Cu has 3d^10, Ag has 4d^10, Au has 5d^10). Therefore, this set is classified as transition elements.
### Step 3: Analyze the second set of elements: Fe, Co, Ni
- **Iron (Fe)**: Electronic configuration is [Ar] 3d^6 4s^2
- **Cobalt (Co)**: Electronic configuration is [Ar] 3d^7 4s^2
- **Nickel (Ni)**: Electronic configuration is [Ar] 3d^8 4s^2
All three elements have partially filled d orbitals. Therefore, this set is also classified as transition elements.
### Step 4: Analyze the third set of elements: Zn, Cd, Hg
- **Zinc (Zn)**: Electronic configuration is [Ar] 3d^10 4s^2
- **Cadmium (Cd)**: Electronic configuration is [Kr] 4d^10 5s^2
- **Mercury (Hg)**: Electronic configuration is [Xe] 4f^14 5d^10 6s^2
All three elements have fully filled d orbitals (3d^10, 4d^10, 5d^10). Therefore, this set is classified as non-transition elements.
### Step 5: Analyze the fourth set of elements: Re, Os, Ir
- **Rhenium (Re)**: Electronic configuration is [Xe] 4f^14 5d^5 6s^2
- **Osmium (Os)**: Electronic configuration is [Xe] 4f^14 5d^6 6s^2
- **Iridium (Ir)**: Electronic configuration is [Xe] 4f^14 5d^7 6s^2
All three elements have partially filled d orbitals. Therefore, this set is classified as transition elements.
### Conclusion
From the analysis above, the only set of elements that are classified as non-transition elements is the third set: **Zinc (Zn), Cadmium (Cd), and Mercury (Hg)**.
### Final Answer
The set of elements that are called non-transition elements is: **Zinc (Zn), Cadmium (Cd), and Mercury (Hg)**.
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