Which statements are true? δ for an exothermic reaction is positive. δ for an endothermic reaction is positive. the evaporation of water is an exothermic process. a combustion reaction is exothermic. when energy is transferred as heat from the surroundings to the system, δ is negative. when energy is transferred as heat from the system to the surroundings, δ is negative.

The true statements are for an endothermic reaction is positive, a combustion reaction is exothermic and when energy is transferred as heat from the system to the surroundings, is negative.

Explanation:

There are 2 types of chemical reactions categorized into heat change:

Combustion reactions are defined as the reactions in which a hydrocarbon reacts with oxygen gas to produce carbon dioxide and water. Heat is released during these reactions. Thus, it is considered as exothermic reactions.

Hence, the true statements are for an endothermic reaction is positive, a combustion reaction is exothermic and when energy is transferred as heat from the system to the surroundings, is negative.

there is none because earth is stationary and flat.

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year