The room-temperature electrical conductivity of a semiconductor specimen is 2.8 × 10 4 (ω∙m)–1. if the electron concentration is 2.9 × 1022 m–3 and electron and hole mobilities are 0.14 and 0.023 m2/v∙s, respectively, calculate the hole concentration. (a) 1.24 × 1024 m–3 (b) 7.42 × 1024 m–3 (c) 7.60 × 1024 m–3 (d) 7.78 × 1024 m–3

In a chemical reaction at equilibrium, the rate of the forward reaction the rate of the reverse reaction. if the rate of the forward reaction more products are formed.

Which best describes eras and periods?

Which of the following represents a balanced nuclear equation showing bismuth-212 undergoing alpha decay followed by beta decay? (2 points) superscript 212 over subscript 83 bi yields superscript 4 over subscript 2 he + superscript 208 over subscript 81 tl yields x−superscript 208 over subscript 82 pb + superscript 0 over subscript -1 beta superscript 212 over subscript 83 bi + superscript 0 over subscript -1 beta yields superscript 4 over subscript 2 he + superscript 208 over subscript 81 tl yields x−superscript 208 over subscript 82 pb superscript 216 over subscript 85 as yields superscript 4 over subscript 2 he + superscript 216 over subscript 85 as yields superscript 216 over subscript 85 pb + superscript 0 over subscript -1 beta superscript 212 over subscript 83 bi yields superscript 0 over subscript -1 beta + superscript 208 over subscript 81 tl yields superscript 208 over subscript 82 pb + superscript 4 over subscript 2 he