The  cathode rays was discovered by

By sharing, gaining or losing electrons the atom can achieve

  The combining capacity of an atom is

The atoms of the same element having the same atomic number but different mass numbers is called

Only certain special orbits known as discrete orbits of electrons, are allowed inside the atom was proposed by

An isotope which is used in the treatment of goiter.

The charge of an electron is

The valency of the atoms of elements having a completely filled outermost shell is

 Among the following which has a definite  shape?

Maximum number of electrons that can be accommodated in the L shell is