Question

3. What is Photoelectric effect? What is stopping potential? Explain cutoff wavelength? What is the cut off wavelength (he) for a photoelectric materials of work function 1.3 eV? 4. Write Bohr's theory and assumptions for hydrogen atom with energy level diagram? What should be the energy of an atomic orbit of n=4? 5. Explain Radioactive rays (a, b, and y) ancd their properties? What is decay constant and decay rate? Calculate decay constant of a radioactive materials of half-life (T1/2) equals to 100 ns?

Answer 1

power is low and Range by (2) In Beta partice, penetrating power is medium and Ionising power is low and Range in air is approx. to 1 metre. (3) In Gramma particle penetrating power is high and Ionising very in air is less than 1 km. Decay constant determines the rate of is denoted d. This constant decay - Decay constant probability may vary greatly between different types of nudei, Leading desay different many rate is dependent upon radioactive aloms in terms of chemical kinetics. 0.693 life d d=0.693 0.693 -) 0-693 X10 observed to the rates. the number Decay rate is of tyy where ty half time = loons 가수 0) ty 100x109 2 mo