Scientists use models to show the characteristics of compounds. Of the different models,ball-and-stick model and space-filling model are commonly used but similar. Ball-and- stick model shows the bond between both atom and not the relative size of the atoms. Space-filling model shows the relative size of the atom and not the bond between the atoms. Both are 3-Dimensional and use color spheres within the model.
Correct answer: "A. Energy from an outside source is continuously being added."
An endothermic reaction is a reaction that is characterised by the system absorbing energy from its surroundings. That energy is usually in heat form. For example, when mixing water<span> with potassium chloride, this reaction will absorb heat and the container will feel cold - endothermic reaction.</span>
Decreasing the turns of wire