Question

A.6 A term symbol "Be contains three numbers or symbols a, B, C. [2] (a) What does a term symbol describe? Explain the meaning of each of a, B and c. (b) Silicon has electronic configuration [1s22s22p6]3s23p2. What is the term symbol for its ground state according to Hund's rules?

Answer 1

# Solution : -A term symbol contains three numbers -sti a). Term symbol is an description of the Congular momentum quantum numbers in a multi- electron atom. Term Sysnbals assumes LS.coupling *** ky a Mass number identifies the number of Riotos and neutrons B → Element symbol. To represent full name Page - ] _ of element

Lc → Atomic number - dentifies the number of Protons. B → Boron a mass number c₃ atomic numbes b). Griven : - Silicon hos electronic.conf Si = [ls? 2o%256) 38:35". - I last shell have - two electrons b² = etili i & me = 1+0=1 mo 1 2 2 2 2 £ mg = 1 + 1 - 1 We Know J = 12+ sl to IL-sl J-VILLO_11-11 -_- JZobye 2 Melo- Page 2 ZO . Opinell ----------I ---------- for p ² less then half filled take lowest L value of I for ground state / s spin L orbital Angularme. J-> total angular mom

2=1, J = 0, 1 = 1 term symbol is 21+ Po l=0, L=s 1=1, L=2 1=2, L =D