2. Information to annotate Diagram.
The core of the sun is approx 15,000,000 degrees Kelvin.
The sun gives out heat by turning Hydrogen into Helium (it loses about 4,000,000 Hydrogen tons per second doing this)
All the energy is created in the core of the sun, this energy is transferred to the surface by radiation. However we receive the heat in the form of Radiation.

3. What is the Photosphere
The photosphere is the lowest layer of the solar atmosphere.
The photosphere is many miles thick.
The photosphere is not solid. You would fall right through! ...and the Sun is very hot (about 6,000 degrees Kelvin). Ouch!

4. The Chromosphere. The chromosphere is 2000-3000 km thick.
It glows faintly relative to the photosphere and can only be seen easily in a total solar eclipse.
In an eclipse you will see it as a
red colour

5. The Corona.
The corona is the final (and exterior) layer of the three regions that make up the sun's atmosphere.
The corona is the widest of all three regions of the sun's atmosphere, and it extends for several million miles from the photosphere and chromosphere.
At an average of 2 million
degrees Kelvin, the corona is by
far the hottest of the sun's layers.
Scientists are still unable to explain
why it's so hot.
The corona is best seen in X-ray images
of the sun and during solar eclipses.