A certain unimolecular reaction is zero order. If the half-life of this reaction is 45 seconds, how long will it take for the reaction to be 70% complete

Fill in the coefficients that will balance the following reaction: a0cr2(so4)3 + a1agno3

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.

Explain in detail of the four major scientific developments that spurred the formulation of the plate tectonics theory