Potassium chloride is a crystal with lattice spacing of 0.314 nm. The first peak for Bragg diffraction is observed to occur at 12.8°. (a) What energy x rays were diffracted? (b) What other order peaks can be observed (0 ≤ 90°)?

If the tunneling current is 8.7 pA when an STM probe is 0.40 nm from a surface and 17 pA when the probe is 0.5 nm from the surface, calculate the current on moving the tip in 0.10-nm steps from 0.40 nm to 1.50 nm.

Young's experimental setup can be used to monitor the width of the lead wires in transistors. The cables are placed in a narrow opening as shown in the figure. The opening is illuminated with highly coherent light. The position of the tenth maximum is measured on a screen located at 0.5m. The expected diameter of the wires is 0.100±0.005 mm. (a) What is the maximum deviation that the position of the tenth maximum can have so that the cable has an acceptable diameter? What would happen if the first maximum was used as the criterion, would the decision be easier or more difficult?

Molybdenum has a work function of 4.20 eV. What is the stopping potential if the incident light has a wavelength of 180 nm?