Which beaker the model contain solutions of ionic substances

Consider the four elements above. which one of these elements will combine with oxygen in a 1: 1 ratio?

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.

Which symbol can be used to indicate the pressure at which a chemical reaction is carried out? 25°c 2 atm pa