7.2.1 The Sun True/False

The high temperature in the core required to sustain nuclear reactions in stable stars is maintained by gravitational forces.

All life on Earth depends on the energy provided by the Sun.

The Sun is the closest star to Earth.

The Sun is currently in an unstable phase.

The Sun mainly consists of hydrogen and helium.

The radiant energy emitted by the Sun is mostly in the X-ray region.

Nuclear reactions in stars like our Sun involve the conversion of helium into hydrogen.

All stars are hot and dense enough for nuclear fusion to occur.

The energy generated in the core of stars is confined to the core itself.

Stars vary in age, size, mass, surface temperature, colour, and brightness.

Stars that are white or blue are generally cooler than those that are red or yellow.

Colour and brightness of stars do not depend on surface temperature.