Bond Enthalpy

[Aryana Sargsyan 2B]

Why do we change the bond enthalpy to negative when a bond is formed?

[Leah Schlageter 1A]

Bond enthalpy is negative because energy is needed to form bonds

[Cassidy Sadowski 3E]

According to Khan Academy, to determine how much energy will be released when we form a new bond rather than break it, we simply make the bond enthalpy value negative.

So, this negative enthalpy demonstrates the energy being released as a result of the new bond formation.

[Jaziel Flores]

Hi Aryana!
I believe that the bond enthalpy is changed to a negative when a bond is being formed because the release of heat/energy makes the chemical reaction available to work. We know that this would mean that it is exothermic. I see this more as a rule, such as to determine how much energy will be released when forming a new bond rather than breaking it.

[Fiorella Garcia 3D]

Bond enthalpy changes to negative when a bond is formed because previously we have learned that when you form a bond you release energy, thus that's why bond enthalpy changes when a bond is formed.

[Varun Sekar 2E]

It is important to note that energy is required to break bonds and energy is released when bonds form. So when a bond is formed, heat/energy is released into the surrounding making the bond enthalpy negative. (Energy leaves the system.)

[Ken Kwok 2J]

Energy is required to break bonds. However, energy is released to the surroundings when bonds are formed as bonds are the more stable state. Since energy is being released, the bond enthalpy is negative.