A mixture of all of the above
1 million K
10 million K
100 million K
At the same temperature and density as the surface.
At the same temperature but denser than the surface.
Hotter and denser than the surface.
Constantly rising to the surface through convection.
Composed of iron.
Gradually expanding in size
Converting kinetic energy into electricity
Converting gravitational potential energy into electricity
Radiation and elements like carbon and nitrogen.
Radioactive elements like uranium and plutonium.
Helium, energy, and neutrinos.
4 million tons
600 million tons
Nothing: mass-energy is conserved.
Attract each other.
Repel each other.
Join together to form a nucleus.
Several years ago.
Tens of years ago.
About a hundred years ago.
About a thousand years ago.
A million years ago.
Gravitational contraction of the Sun
Wave motions in the solar interior
Variations of the solar thermostat
The winding of magnetic field lines due to variations in the Sun's rotation
The Sun becomes much brighter.
The Sun emits light of longer average wavelength.
The Sun rotates faster at the equator.
We see many sunspots on the surface of the Sun.
All of the above