An equivalent definition can be based on the fact that an exposure of one roentgen deposits 8.30 x 10-3 J of energy per kilogram of dry air. Using the two definitions and assuming that all ions produced are singly charged, determine the average energy (in eV) needed to produce one ion in air.
To determine the average energy needed to produce one ion in air, we can use the given definition of exposure in roentgen and convert it to energy in joules. Then we convert the energy in joules to electron volts (eV).
1. Start with the given information:
- Exposure of 1 roentgen deposits 8.30 x 10^-3 J/kg of dry air.
2. Convert from joules to eV:
- 1 eV = 1.602 x 10^-19 J
- Multiply the energy in joules by (1 eV / 1.602 x 10^-19 J) to convert it to eV.
3. Calculate the energy per kilogram of dry air:
- Multiply the energy in eV by the factor (1 kg / 8.30 x 10^-3 J) to find the energy per kilogram of dry air.
4. Determine the average energy needed to produce one ion:
- Since all ions produced are singly charged, the average energy needed to produce one ion is equal to the energy per kilogram of dry air.
By following these steps, you can calculate the average energy needed to produce one ion in air based on the given definitions and conversions.