Even though ozone may be dangerous to our health here on earth, how can it be beneficial in the upper atmosphere?

It absorbs ultraviolet (UV) radiation from the sun.

Explanation:

Excess UV radiation damages DNA, causing malignant skin cancers.

The ozone in the upper atmosphere is beneficial because it absorbs much of this harmful radiation.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.