State how electrons are distributed in an atom. Explain in brief the rules which govern their distribution.

The electron distribution in an aluminium atom is

Which of the following show restricted distribution?

Show diagramatically the electron distributions in a sodium atom and a sodium ion and also give their atomic number.

Write down the electron distribution of chlorine atom. How many electrons are there in the L-shell ? Atomic number of chlorine is = 17.

Electrons are distributed in different energy shells, according to the rules of ..........scheme.

In the Thomson's model of atom, which of the following statement are correct ? (i) The mass of the atom is assumed to be uniformaly distributed over the atom. (ii) The positive charge is assumed to be uniformaly distributed over the atom. (iii) The electrons are uniformaly distributed in the positively charged sphere. (iv) The electrons attract each other to stabilise tha atom.

State True or False: Subtraction distributes over division.

State True or False: Division distributes over addition

Choose the correct alternative form the clues given at the end of each statement: (a) The size of the atom in Thomson's model is ........... the atomic size in Rutherford's model (much greater than/no different form/much less than) (b) In the ground state of ..........., electrons are in stable equilibrium, while in.......... electrons always experience a net force (Thomson's model/Rutherford's model). (c) A classical atom based on ......... is doomed to collapse (Thomson's model/Rutherford's model). (d) An atom has a nearly continuous mass distribution in ......... but has highly non uniform mass distribution in....... (Thomson's model/Rutherford's model). (e) The positively charge part of the atom possesses most of the mass of the atom in .......... (Rutherford's ,model /both the models).

Name the three constituents of an atom and state mass and charge of each. How are they distributed in an atom ?