When a atom gets smaller, what happens to the electronegativity ?

Increases electronegativity.

Explanation:

Hit that Thanks button, pls.

<Nathen>

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.

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.