What causes the recognition of an element from its energy signature? O
A. Each element emits radiations at random frequencies.
B. Each element emits energy that can be transformed into sound.
C. Each element emits electromagnetic waves that travel faster than light.
D. Each element emits electromagnetic waves at a unique set of wavelengths.

I'm so sorry if this is wrong but I think its B

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.