In Rutherford's alpha scattering experiment using gold foil, the kinetic energy of the alpha particle was 1.2 x 10-12J. For a head on collision, using the formula K.E. = x 2Ze2/r0 , what may be the magnitude of r0 [ The nuclear radius of gold, Z=79; = 9 x 109 new-ton/meter2 coulomb-2, e= 1.6x10-19 coulomb]
1. 3 x 10-14m
2. 1.3 x 10-14m
3. 2.1 x 10-14m
4. 4.3 x 10-14m
If frequency of the X-rays produced using an element as anti-cathode is found to be 2500 sec-1, the atomic number of used element is (a, b= 1)
1. 51
2. 49
3. 56
4. 72
When the atoms of gold sheet are bombarded with a beam of -particles, only a few a-particles get deflected where as most of them go straight undeflected. This is because:
1. | The force of attraction on the -particles by the oppositely charged electron is not sufficient. |
2. | The nucleus occupies much smaller volume as compared to the volume of atom. |
3. | The force of repulsion on fast moving -particles is very small. |
4. | The neutrons in the nucleus do not have any effect on -particles. |
An element with atomic mass Z consists of two isotopes of mass number Z-1 and Z + 2. The percentage abundance of the heavier isotope is -
1. 0.25
2. 33.3
3. 66.6
4. 75
Two isotopes of Boron are found in the nature with atomic weights 10.01(I) and 11.01(II). The atomic weight of natural Boron is 10.81. The percentage of (I) and (II) isotopes in it are respectively-
1. 20 and 80
2. 10 and 90
3. 15 and 75
4. 30 and 70
Rutherford's scattering experiment is related to the size of the-
1. Nucleus
2. Atom
3. Electron
4. Neutron
Arrange the following particles in increasing order of values of e/m ratio: Electron(e), proton(p), neutron(n) and α-particle(α)
1. n,p,e,α
2. n,α,p,e
3. n,p,α,e
4. e,p,n,α
Mass of neutron is ........................times the mass of an electron-
1. 1840
2. 1480
3. 2000
4. None of the above
Isodiaphers among the following options is :
1. and
2. and
3. and
4. and
The incorrect statement regarding the characteristics of X-rays is :
1. The radiation can ionize the gas
2. It causes a fluorescence effect on ZnS
3. It is deflected by electric and magnetic fields
4. Have a shorter wavelength than ultraviolet rays