Atomic and Nuclear Physics Answers

The doctor measured the count rate from the sample. the count rate was 80 seconds per second.

half life of radium-226 = 1600years

calculate the count rate in 6400 years

Describe the mode of operation of one instrument which uses the radiation heat transfer

mechanism

13.Electron are accelerated in a television tube through a potential difference of 9.8kV. Find the highest frequency and minimum wavelength of the electromagnetic wave emitted, when these strike the screen of the tube. In which region of the spectrum will these lie? a. Differentiate X-rays and visible light in terms of the origin of these EM radiations. b. What voltage must be applied to an X-ray tube for it to emit X-rays with minimum wavelength 0.5 A˚ ?

Find the kinetic, potential, and total energies of the hydrogen atom in the first excited level, and find the wavelength of the photon emitted in the transition from the first excited level to the ground level.

.Find the yield and estimate the average cross section for the (a, n) reaction excited by 7 MeV a-particles in a thick aluminum target if 1.60 × 109 neutrons are emitted per second. The a-particle current is 1.56 1014 s-1

(A) Explain how pure metal and a semi conductor can be distinguished through the effect of temperature on their electrical resistance

(B) explain what is meant by (I) an n-semi conductor (ii) a p-semiconductor

(C) state two advantages and one disadvantage of a junction diode over a thermionic valve

Calculate the molar mass of a liquid if 0.995g if it’s vapour occupy 250L at 200 degree cent and 45.0Torr

Activity 3: Gravitational Force

The mass of m1 of one of the small sheres of a Cavendish balance is 0.02 kg, the

mass m2 of the nearest large sphere is 0.065 kg, and the center-to-center distance

between them is 0.04 m. Find the gravitational force Fg on each sphere due to the other.

A 0.15kg tumor is treated with α

α particles. There are 2×10

12

2×1012 particles reaching the tumor every second, each having energy 3×10

−15

3×10−15J. What is the absorbed dose given to the tumor

A 2.0kg piece of meat is treated with 1.5kGy in order to kill bacteria and preserve its shelf life. How much energy is absorbed by the meat?