The wavelength of a electron and a neutron will become equal when

the velocity if a electrons is x time. The velocity of neutronthe value of x is ----------- (nearest integer)

• 1758

• 1578

• 8571

• 1758

Which of the following has a positive charge?

• Protron

• Neutron

• Onion

• None of ththe above

Rutherford carried out experiments in which a beam of alpha particles was directed at a thin piece of metal foil. From these experiments he concluded that:

• electrons are massive particles.

• the positively charged parts of atoms are moving about with a velocity approaching the speed of light.

• the positively charged parts of atoms are extremely small and extremely heavy particles.

• the diameter of an electron is approximately equal to that of the nucleus.

The maximum number of electrons that can be accommodated in a sublevel for which l = 3 is:

• 2

• 4

• 10

• 14

Naturally occurring rubidium consists of just two isotopes. One of the isotopes consists of atoms having a mass of 84.912 amu; the other of 86.901 amu. What is the percent natural abundance of the heavier isotope?

• 15%

• 28%

• 37%

• 72%