1. Specific Heat Capacity

* Water has a specific heat capacity of 4.184 J/g°C. This means it takes 4.184 Joules of energy to raise the temperature of 1 gram of water by 1 degree Celsius.

2. Temperature Change

* The temperature change is the difference between the boiling point of water (100°C) and room temperature (20°C): 100°C - 20°C = 80°C

3. Mass

* You have 1.0 kg of water, which is equal to 1000 grams (1 kg = 1000 g).

4. Calculation

* Heat Energy (Q) = mass (m) x specific heat capacity (c) x temperature change (ΔT)

* Q = 1000 g x 4.184 J/g°C x 80°C

* Q = 334,720 Joules

Therefore, you need approximately 334,720 Joules of heat energy to raise 1.0 kg of water from 20°C to its boiling point (100°C).