When two compounds react, what other change can you expect?

When two compounds react, one significant change you can expect is a change in temperature. Chemical reactions often involve energy transformations, and this can manifest as an increase or decrease in temperature, depending on whether the reaction is exothermic or endothermic.

In exothermic reactions, energy is released in the form of heat, leading to an increase in temperature of the surroundings. Conversely, in endothermic reactions, energy is absorbed from the surroundings, resulting in a decrease in temperature. This temperature change is a fundamental observation in many chemical reactions, allowing scientists to infer the nature of the reaction occurring.

Static charge formation, separation into individual atoms, and the presence of non-reactive intermediates do not universally occur in all reactions. While these may happen in specific circumstances or types of reactions, they are not definitive changes you can expect in the majority of chemical reactions, making the change in temperature the most reliable and relevant outcome to consider.