Electron drift mobility in tin (sn) is 3.9 cm2 v-1 s-1. the room a. temperature (20 c) resistivity of sn is about 110 nq m. atomic mass mat and density of sn are 118.69 g mol-1 and 7.30 g cm-3, respectively. how many "free" electrons are donated by each sn atom in the crystal? how does this compare with the position of sn in group ivb of the periodic table? b. consider the resistivity of few selected metals from groups i to iv in the periodic table in table 2.7. calculate the number of conduction electrons contributed per atom and compare this with the location of the element in the periodic table. what is your conclusion? table 2.7 selection of metals from groups i to v in the periodic table density resistivity (n2 m mobility (cm2v-s periodic metal group valency (g cm na ia 0.97 42.0 53 mg ag zn па 2 1.74 44.5 17 ib 1 10.5 15.9 56 iib 2 7.14 59.2 8 al шв 2.7 26.5 12 sn ivb 4 7,30 110 3.9 pb ivb 4 11.4 206 2.3 note: mobility from hall-effect measurements