The maximum number of electrons in a shell of number 'n' is given by.
2n
22n
2n2
n3
The total number of nucleons in the nucleus are called:
mass number
atomic number
Number of neutrons
None of these
Why is the cathode ray tube evacuated to a low pressure?
To avoid the effect of external electric field on the beam of electrons.
To increase the energy of the beam of electrons.
To avoid collisions of electrons with the air molecules
To increase the rate of emission.
Which of the following is not a primary colour?
Red
Green
Yellow
Blue
Which element has largest number of isotopes?
Lead
Carbon
Chlorine
Tin
The difference between the expected and actual mass of an alpha particle is 0.02928 u. How much is the binding energy per nucleon for alpha particles ?
5 MeV
7.5 MeV
9.8 MeV
6.81 MeV
The rate of emission of electrons from a surface does not depend upon:
the temperature of surface
the shape of metal surface
the nature of the metal surface
the surface area of metal
The atoms of the same element which have the same atomic number Z, but differ in their mass number is called
Isotopes
Isotones
Isobars
Nucleons
Choose the work function of Platinum.
6.2
4.52
4.37
2.6
A certain nucleus X has a mass number 15 and atomic number 7.Find the number of neutrons.
15
7
8
22
