No they each have its own orbit around the sun and they do not collide
They are in their own orbit
No. Planets cannot share the same orbit. If they did, they would collide.
As the planets orbit the sun, its gravity keeps them from colliding
Planets orbit at least something. If they don't, they will collide with something else which will cause a big explosion. Planets such as Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, all orbit the sun.
Planets around the sun in nearly circular orbit . The radii of these orbits differ widely
planets will fall to the outer space ,they will collide with each other and they will melt or exploded
The distance of the planets from the sun does not change because of the gravity surrounding each planet is pulling them into continuous orbit.
If they did then they would collide. They could merge into a larger planet or get blasted into space. In the latter case, the smaller parts would continue in individual orbits until they were attracted, by gravity, into other planets or coalesce into a new planet.
No they do not cross and they do not leave their orbit, which means the state it has been right now will last forever.
Any moon is held in orbit by gravity, just as the planets are held in orbit around the sun by gravity.
no not at all any planets has not straightorbit
I am not familiar with planets evolving around any singular planet. If you are referring to orbit, the planets orbit the sun, a star, not a planet, in our solar system. Some planets have moons in their orbit.