What is incorrect about the resting state of neuron ?

Options

A. High concentration of `K^(+)` and negatively charged proteins and low concentration of `Na^(+)` in axoplasm.
B. Axonal membrane is nearly impermeable to `Na^(+)` .
C. Axonal membrane is more permeable to `K^(+)`.
D. Outer surface of axon is negatively charged.

Answer

To determine what is incorrect about the resting state of a neuron, we need to analyze the provided options based on the characteristics of a neuron during its resting potential.

### Step-by-Step Solution:

1. **Understanding Resting Potential**:
- A neuron at rest has a specific distribution of ions across its membrane. The inside of the neuron (axoplasm) is negatively charged relative to the outside.
- The resting potential is typically around -70 mV.

2. **Analyzing the Options**:
- **Option 1**: High concentration of potassium and negatively charged proteins, and low concentration of sodium in axoplasm.
- This statement is **correct**. The inside of the neuron has a high concentration of potassium ions (K+) and negatively charged proteins, while sodium ions (Na+) are in lower concentration inside.

- **Option 2**: Axonal membrane is nearly impermeable to sodium.
- This statement is also **correct**. During resting potential, the axonal membrane does not allow sodium ions to enter, making it relatively impermeable to sodium.

- **Option 3**: Axonal membrane is more permeable to potassium.
- This statement is **correct** as well. The membrane is more permeable to potassium ions, which can move out of the neuron, maintaining the negative internal environment.

- **Option 4**: Outer surface of axon is negatively charged.
- This statement is **incorrect**. The outer surface of the axon is positively charged during resting potential, while the inner surface is negatively charged.

3. **Conclusion**:
- The incorrect statement about the resting state of a neuron is that the outer surface of the axon is negatively charged.

### Final Answer:
The incorrect statement about the resting state of a neuron is: **The outer surface of axon is negatively charged.**