The reaction A → B + C is known to be zero order in A with a rate constant of 5.0 × 10–2 mol/L·s at 25°C. An experiment was run at 25°C where [A]0 = 1.0 × 10–3 M. What is the concentration of B after 5 × 10–3 sec?

A. 5.0 × 10–4 M

B. 7.5 × 10–4 M

C. 5.0 × 10–5 M

D. 2.5 × 10–4 M

E. None of these choices are correct.

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