1. What is Distance of Closest Approach?

Definition: The distance to which an alpha particle comes closer to the nucleus in atomic physics.

Purpose: This calculation helps in understanding atomic scattering experiments and nuclear physics.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( r_0 \) — Distance of closest approach (meters)
• \( q \) — Charge (in multiples of electron charge)
• \( e \) — Electron charge (1.602 × 10⁻¹⁹ C)
• \( \epsilon_0 \) — Permittivity of vacuum (8.854 × 10⁻¹² F/m)
• \( E_{pair} \) — Electrostatic potential energy between ion pair (Joules)

Explanation: The formula calculates the minimum distance between charged particles based on their electrostatic interaction.

3. Importance of Distance Calculation

Details: Understanding the closest approach distance is crucial in atomic physics, particle scattering experiments, and nuclear reaction studies.

4. Using the Calculator

Tips: Enter the charge (in multiples of electron charge) and the electrostatic potential energy in Joules. The energy should be negative for attractive forces.

5. Frequently Asked Questions (FAQ)

Q1: What units should I use for the inputs?
A: Charge should be in multiples of electron charge (unitless), and energy should be in Joules.

Q2: What's the significance of negative energy?
A: Negative energy indicates an attractive force between the particles.

Q3: What's a typical range for this distance?
A: For atomic scales, it's typically in the range of 10⁻¹² to 10⁻⁹ meters.

Q4: Can I use this for repulsive forces?
A: Yes, but the energy value should be positive for repulsive interactions.

Q5: Why is the electron charge squared in the formula?
A: The electrostatic force depends on the product of both charges (Coulomb's law).