A scientist is studying a previously unknown chemical reaction. She concludes that it is exothermic. What must the scientist hav
e observed? The reaction released heat.
The reaction formed a gas.
The reaction sped up when a catalyst was added.
The reaction caused the container to get cold.
I think the correct answer from the choices listed above is the first option. She concluded that the reaction is an exothermic one because t<span>he reaction released heat. Exothermic is when heat goes out of the system. The opposite is referred to as an endothermic reaction.</span>
