Positive charge is carried by

Outermost shell of an atom cannot accommodate more electrons than

The charge to mass ratio on cathode rays in the discharge tube is constant because electrons are common constituents of all matter.

Calcium has 20 electrons.These K, L, M and N shells.Which shell or shells are incomplete?

Rutherford's alpha-particle scattering experiment was responsible for the discovery of

Substance having similar chemical properties, but different physical properties are called ______

The negative particle discovered by J.J.Thomson was given name ........

E.Rutherford used ............ particles in his scattering experiments

According to Rutherford, the force of attraction between the moving electrons and ............. is counter balanced by the centrifugal force of electrons.

Almost all the mass of an atom is concentrated in a small region of space called ...........

If an atom contains one electron and one proton, will it carry any charge or not?

How is the flow of current in a cathode ray experiment explained knowing that gases are bad conductors of electricity?

What are the important properties of anode rays?

State three characteristics of Canal rays.

What is a proton?What are its characteristics?

In what respects cathode rays differ from positive or anode rays?

State the three rules that are followed for determining the number of electrons in different energy levels or shells in an atom.

How do you define valency of an atom?

What are the uses of isotopes?

Define the term "Half-life".

A radioisotope has half-life of 900 seconds.Calculate the fraction of original isotope which would remain behind after four half-life periods.

Summarise the rules for writing of distribution of electrons in various shells for the first eighteen elements.