Answer :
Final answer:
The middlemost layer of the Sun's atmosphere, transitioning from the chromosphere to the corona, experiences a sharp temperature increase from about 20,000 degrees Celsius to up to 2,000,000 degrees Celsius.
Explanation:
The temperature of the middlemost layer of the Sun's atmosphere is best described by considering the layers above the photosphere. The photosphere has a temperature of about 6000°C, while the region above it, the chromosphere, leads into the transition region. It is in the transition region where the temperature climbs sharply from around 10,000 K (typical of the chromosphere) to nearly a million degrees. Following this, the corona, which is the outermost layer of the Sun's atmosphere, has a temperature ranging from 1 million to 2 million degrees Celsius. Therefore, the correct answer is that the temperature of the middlemost layer of the Sun's atmosphere increases from 20,000 degrees Celsius to 2,000,000 degrees Celsius as it transitions from the chromosphere to the corona.
