Considering the graph of 1s , choose the correct option:

Options

A. `Psi` is zero when`r cancel(=) 0`
B. `Psi` is maximum when `r cancel(=) 0`
C. maxima is at surface
D. `Psi` have negative sign

Answer

To solve the question regarding the graph of the 1s orbital, we will analyze the given options step by step.

### Step-by-Step Solution:

1. **Understanding the Graph of 1s Orbital**:
- The graph of the 1s orbital represents the wave function (psi, ψ) as a function of the radial distance (r) from the nucleus.
- The x-axis represents the radial distance (r), and the y-axis represents the wave function (ψ).

2. **Analyzing the First Option**:
- **Option**: "ψ is 0 when r is not equal to 0."
- **Analysis**: As r approaches infinity, ψ tends to zero. However, ψ is not zero for all values of r except at infinity. Therefore, this statement is misleading. The correct interpretation is that ψ is not zero at all points except at infinity.
- **Conclusion**: This option is **incorrect**.

3. **Analyzing the Second Option**:
- **Option**: "ψ is maximum when r is not equal to 0."
- **Analysis**: The maximum value of ψ occurs at r = 0, not when r is not equal to 0. As r increases, ψ decreases and approaches zero as r approaches infinity.
- **Conclusion**: This option is **incorrect**.

4. **Analyzing the Third Option**:
- **Option**: "Maxima is at surface."
- **Analysis**: The maximum value of ψ occurs at the center (r = 0), not at the surface. The surface refers to larger values of r where ψ is not at its maximum.
- **Conclusion**: This option is **incorrect**.

5. **Analyzing the Fourth Option**:
- **Option**: "ψ has a negative sign."
- **Analysis**: The wave function ψ for the 1s orbital is positive for all values of r (except at infinity). Therefore, this statement is also incorrect.
- **Conclusion**: This option is **incorrect**.

### Final Conclusion:
- The only correct option is that ψ is zero when r approaches infinity (not when r is not equal to zero). All other options are incorrect.

### Correct Answer:
- The correct option is: **None of the options provided are correct.**