Final answer:
The temperature of the Sun's core is not about 20,000 K; it is actually approximately 15 million K, which is required for the nuclear fusion processes that generate the Sun's energy.
Step-by-step explanation:
The statement that the temperature of the Sun's core is about 20,000 K is false. In reality, the temperature at the core of the Sun is approximately 15 million K. This high temperature is necessary for nuclear fusion, the process that powers our Sun, and nearly all of this energy is generated within a region that extends outwards from the core by about 150,000 kilometers, which is less than 10% of the Sun's total volume. In contrast to the core, the surface temperature of the Sun is significantly cooler at about 5750 K.