Question

a) Write the ground state electron configuration of P (Z = 15) and point out its valence electrons.

b) Suppose that the interatomic potential between two phosphorus atoms at distance r is given by

$E_{n} (r) = -\frac{A}{r^6} + \frac{B}{r^1^{2}}$

where A and B are positive constants. Calculate:

(1) repulsive force Fr and attractive force Fa versus distance r between the two atoms

(2) equilibrium distance between the two atoms, r0, and bonding energy, E0

Answer 1

solution e (a) fos P 2 - electronic configuration is 1s? 25² 2p6°352 3p3 A neutral phosphorus celom conten's 5 valence eleiekons (b) Enla) = - As + 2 12 - LO) Put r=ko : TR $13 Put ko = (20 315 in equation Hen E=Eo B ,1215 Ex= - AxA675 215 x B (918) Aus Amos C901676 4 A 25 x B1981

for attractive For de forces er ) Simillarly , lepulsive force is Fe = alter d& -12 B