Who first time ruled out the existence of definite paths of electrons ?

Options

A. de-Broglie
B. Heisenberg
C. Neils Bohr
D. Einstein

Answer

To solve the question "Who first time ruled out the existence of definite paths of electrons?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question is asking for the scientist who first ruled out the idea that electrons have definite paths or trajectories.

2. **Identify Relevant Concepts**: The concept of electron paths is related to quantum mechanics, particularly the Heisenberg Uncertainty Principle. This principle states that it is impossible to know both the position and momentum of a particle with absolute certainty.

3. **Recall Key Scientists**: The question provides options that include notable physicists: D. Broglie, Heisenberg, Niels Bohr, and Einstein. We need to determine which of these scientists is associated with the ruling out of definite paths for electrons.

4. **Analyze Each Option**:
- **D. Broglie**: Proposed the wave-particle duality of matter but did not rule out definite paths.
- **Heisenberg**: Formulated the Heisenberg Uncertainty Principle, which indeed rules out the existence of definite paths for electrons.
- **Niels Bohr**: Developed the Bohr model of the atom, which suggests fixed orbits for electrons.
- **Einstein**: Known for the theory of relativity and contributions to quantum theory, but not specifically for ruling out electron paths.

5. **Conclude the Correct Answer**: Based on the analysis, the scientist who first ruled out the existence of definite paths of electrons is **Heisenberg**.

### Final Answer:
The correct answer is **Heisenberg**.

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