To determine which of the following elements will form an acidic oxide, we need to analyze the electronic configurations of the elements based on their atomic numbers. Here’s how to approach the problem step by step:
### Step-by-Step Solution:
1. **Identify the Elements and Their Atomic Numbers**:
List the atomic numbers provided in the question. For this example, let's assume the atomic numbers are 3, 7, 12, and 19.
2. **Write the Electronic Configurations**:
- For atomic number 3:
- Electronic configuration = 2,1
- For atomic number 7:
- Electronic configuration = 2,5
- For atomic number 12:
- Electronic configuration = 2,8,2
- For atomic number 19:
- Electronic configuration = 2,8,8,1
3. **Determine the Number of Valence Electrons**:
- Atomic number 3 (2,1) has 1 valence electron.
- Atomic number 7 (2,5) has 5 valence electrons.
- Atomic number 12 (2,8,2) has 2 valence electrons.
- Atomic number 19 (2,8,8,1) has 1 valence electron.
4. **Identify Non-Metals**:
Non-metals typically have 4 to 8 electrons in their valence shell. From the above:
- Atomic number 3: 1 valence electron (metal)
- Atomic number 7: 5 valence electrons (non-metal)
- Atomic number 12: 2 valence electrons (metal)
- Atomic number 19: 1 valence electron (metal)
5. **Conclusion on Acidic Oxide Formation**:
Since only the element with atomic number 7 has 5 valence electrons and is classified as a non-metal, it will form an acidic oxide.
Thus, the correct answer is the element with atomic number 7.
### Final Answer:
The element that will form an acidic oxide is the one with atomic number 7.
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