Evolution — BIOLOGY STD 12 Science — Question

1. 6000

Explanation:

The sun is 4.6 billion years old. It is largely composed of hydrogen and helium. The surface of the sun is called photosphere. The photosphere gives off the sun's energy in forms of heat and light. Sunspots on the photosphere are cooler and darker than the surrounding area.

The temperature at the surface of the sun is about 60000C. The temperature rises from the surface of the sun inwards towards the very hot center of the sun, where it reaches about 15,000,000 centigrade.

The temperature of the sun also rises from the surface outward into the solar atmosphere. The uppermost layer of the solar atmosphere, called corona, reaches temperatures of million of degrees.