Which of the following is an oxidation-reduction reaction? A) HBr(aq) + NaOH(aq) → NaBr(aq) + H2O(l)
B) NaI(aq) + AgNO3(aq) → AgI(s) + NaNO3(aq)
C) Pb(C2H3O2)2(aq) + 2 LiBr(aq) → PbBr2(s) + 2 LiC2H3O2(aq)
D) Ba(s) + 2 HCl(aq) → BaCl2(aq) + H2(g)
E) All of the above are oxidation-reduction reactions.

Use the periodic table to determine the electron configuration of dysprosium (dy) and americium (am) in noble-gas notation.

Achemistry student weighs out 0.306 g of citric acid (h3c6h5o7), a triprotic acid, into a 250 ml volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with 0.1000 m naoh solution. calculate the volume of naoh solution the student will need to add to reach the final equivalence point. be sure your answer has the correct number of significant digits.

Two metal blocks that have slightly different temperatures are placed next to one another. after five minutes, they both have lower but equal temperatures. according to the law of conservation of energy, what  most likelyhappened? energy was created inside the blocks.energy was destroyed inside the blocks.energy was absorbed into the blocks from outside the system.energy was transferred from the warmer block to the cooler block.