Standard enthalpy of formation

[kennedyp]

Why exactly is the standard of formation of an element in its most stable form 0?

[Megan Vu 1J]

The standard enthalpy of formation for a stable element is zero because since it is diatomic, it requires no energy in order to form. Diatomic gases such as O2, I2, H2, and so forth are natural and form without needing energy, making it extremely stable.
To form an O2 for example, O2 -> O2, and there is no change in energy releasing.

[haileyramsey-1c]

The standard enthalpy of formation is zero because it is naturally occurring in its diatomic state. Since this state is preferred as it is more stable it requires no energy to form. Standard enthalpy of formation is the change in enthalpy when one mole of a substance is formed at 25 degrees celsius and 1atm. Since it is defined under these conditions, an element is the most stable. But, if conditions were to change another form of a substance may be more stable.

[Ryan Lee 1E]

Yeah, as people have said, diatomic molecules are the in their most stable form, which means that under normal conditions, they already exist in this state. Therefore, it doesn't require additional energy to form them.

[Katie Bart 1I]

Because elements exist in the form that requires the least amount of energy, so in their natural state, the standard enthalpy of formation would be zero.

[005384106]

As Lavelle talked about in lecture, Why is graphite the most stable form of carbon?

[005384106]

During Friday’s lecture, is method 3 a way to solve for enthalpy formation by subtracting the enthalpy of products by reactants?