Which of the following statement about transuranic elements is incorrect?

Options

A. These are all synthetic elements
B. These are elements of atomic number 93 and beyond
C. Elements from 92 to lawrencium are called actinides
D. These are part of fourth transition series

Answer

To determine which statement about transuranic elements is incorrect, we first need to understand what transuranic elements are. Here's a step-by-step solution:

### Step 1: Define Transuranic Elements
Transuranic elements are defined as the elements that have an atomic number greater than 92. This means they start from atomic number 93 and go up to the highest known atomic number, which is currently 118.

**Hint:** Remember that transuranic elements are those elements that come after uranium (atomic number 92).

### Step 2: Analyze the Options
Now, let's analyze the provided options one by one:

1. **Option 1:** "These are all synthetic elements."
- This statement is partially correct. While many transuranic elements (like Neptunium, Plutonium, etc.) are synthetic, not all transuranic elements are synthetic. For example, Uranium (atomic number 92) is naturally occurring. However, the statement does not specify "all" transuranic elements, so it can be considered correct in the context of synthetic elements being primarily found among transuranic elements.

**Hint:** Consider whether the statement specifies all elements or just a subset.

2. **Option 2:** "These are elements of atomic number 93 and beyond."
- This statement is correct. As established, transuranic elements start from atomic number 93.

**Hint:** Recall the definition of transuranic elements to validate this statement.

3. **Option 3:** "Elements from 92."
- This statement is incorrect. Transuranic elements do not include atomic number 92 (Uranium); they start from atomic number 93.

**Hint:** Focus on the definition of transuranic elements and their starting point.

4. **Option 4:** "These are part of the 4th transition series."
- This statement is correct. Transuranic elements are indeed part of the actinide series, which can be associated with the 4th transition series.

**Hint:** Consider the placement of transuranic elements in the periodic table.

### Step 3: Conclusion
From the analysis, the incorrect statement about transuranic elements is **Option 3**, as it incorrectly includes atomic number 92.

**Final Answer:** The incorrect statement about transuranic elements is **Option 3**: "Elements from 92."