The Sun boils off material from the comet and this is seen as a "tail".
Why do comets have tails
No, they do not burn only comets have tails.
No, that would be comets.
yes
Comets
Yes, all comets develop tails when they approach the Sun. The tail forms as the Sun's heat vaporizes the comet's icy nucleus, releasing gas and dust that get pushed away from the comet by solar wind and radiation pressure, creating the characteristic tail.
rocks and dust
It depends on how fast the comet is going.
When they reach the inner solar system.
In the sense that an observer can see tails on comets - no, the gravity and composition of Mars is not favorable to the production of a tail.
yes
Comets