According to Kirchhoff's Voltage Law, what percentage of the available voltage will drop across the load if there is only one load component and a battery?

According to Kirchhoff's Voltage Law, the total voltage in a closed circuit is equal to the sum of the voltage drops across all components within that circuit. In a scenario where there is only one load component and a battery, fundamentally, the entire voltage provided by the battery is applied across the load.

Since there are no other components in the circuit to consume any of that voltage, the entire voltage from the battery is available at the load's terminals. Therefore, the percentage of the available voltage that drops across the load is 100%. This principle works effectively under the assumption of an ideal circuit without any resistance or loss in other components, which aligns with the case presented in the question.

In different scenarios with multiple loads or resistances, the voltage would distribute differently, but in this specific case, the simplicity of just one load allows for the conclusion that the complete voltage is utilized across that single load.