You observe a x-ray line with a wavelength of 0.144 nm.
a. what is the energy of the x-ray photon, in ev?
b. determine which element (name and atomic number) produced the line.
c. if the element found in part (b) was modeled as a bohr atom (that is, with only one electron but the same atomic number), what
would be the energy of the transition of the transition from the n=2 to n=1 state? how does this value compare with your value in
part (a)?

Under conditions for which the same room temperature is maintained by a heating or cooling system, it is not uncommon for a person to feel chilled in the winter but comfortable in the summer. provide a plausible explanation for this situation (with supporting calculations) by considering a room whose air temperature is maintained at 20â°c throughout the year, while the walls of the room are nominally at 27â°c and 14â°c in the summer and winter, respectively. the exposed surface of a person in the room may be assumed to be at a temperature of 32â°c throughout the year and to have an emissivity of 0.90. the coefficient associated with heat transfer by natural convection between the person and the room air is approximately 2 w/m2 â‹…â‹… k. what is the ratio of the thermal resistance due to convection to the thermal resistance due to radiation in the summer? what is the ratio of thermal resistances in the winter

Discuss how the hardness or softness of the landing surface is related to the time required to stop the egg

What happens when a rubber rod is rubbed with a piece of fur?