Which of the following is NOT an exothermic reaction?

A. Dissolving sugar in water to form a mixture of sugar and water
B. The oxidation of iron to form iron oxide
C. The oxidation of zinc to form zinc oxide
D. An exposed metal nail forming rust

a) dissolving sugar in water to form a mixture of sugar and water

Explanation:

exothermic reaction is reaction in which is heat is released during the reaction and endothermic reaction is a reaction in which heat is needed or required for the reaction to take place

all the options excluding option A) is exothermic as during the process of formation of bonds in oxidation, heat is released. rusting too is a slow form of oxidation and thus an exothermic reaction.

dissolving sugar in water is not exothermic reaction because their is no heat released. the sugar molecules simply disperses in the water molecules and form a solution.

trigonal pyramidal

tetrahedral

trigonal planar

bent

why do the isotopes of a particular element behave differently in nuclear reactions but the same in chemical reactions? chemical reactions involve changes to electrons in an atom; isotopes do not differ in electrons, and so they react the same way during chemical changes.