Answer:
The boundary between the Sun's interior and the solar atmosphere is called the photosphere. It is what we see as the visible surface of the Sun.
Explanation:
Photosphere is the part of the Sun is visible by human.
The boundary between the Sun's interior and the solar atmosphere is called the photosphere.
The lower region of the solar atmosphere is called the chromosphere.
The uppermost portion of the Sun's atmosphere is called the corona.
The core is at the centre.
