Question

(a) By means of a simple table, summarise the four quantum numbers that are assigned to electrons con?ned in any atom. (You may ignore the spin angular momentum quantum number which always has the value s = 1 2.) Include a statement of the allowed values of each quantum number. (8 marks )

(b) In your own words, write down: (i) Pauli’s exclusion principle; (ii) Hund’s rule. What other principle needs to be employed in determining the electronic structure of the ground state of an atom? (3 marks )

(c) Very brie?y explain the main horizontal and vertical features of the Periodic Table in terms of the electronic structure and relevant quantum numbers. (4 marks )

(d) Write down in standard notation the electronic structure for the three lightest elements in the penultimate group of the Periodic Table (i.e. the halogens: F, Cl, Br). Hence comment on the chemical characteristics of the elements in this group.

Answer 1