Unlikely in out own solar system, but quite likely in other parts of the universe. Some say that the asteroid belt is a planet that failed to form.
Yes.
There are many other planets in many other galaxies.
Yes, Earth
We don't know about any other other place, besides Earth, that harbors life. But many scientists think that there is life on other planets.
No, there is no oxygen on any other planet other than Earth because there is no planet life on the other planets.
the sun is bigger than any other planets because millions of years ago meteorites smashed together to make the sun and to any other planets that did not happen
No
Earth, Venus, and Mercury are also inner planets.
Other than the Earth, no life has been found on any of the other planets. We are still searching.
Over 900 planets have been discovered orbiting other stars. These are called exoplanets.
No one actually found any human life on any other planets yet, but there is known to be some plant life out on mars.
I suppose maybe... but not strong enough to form into humans, animals or any living thing. So it is impossible to live on other planets. PS, even if there were other organisms, then we would need to exclude Mercury as its too hot, Jupiter, Saturn, Uranus and Neptune as they are either too cold or because they are all gas planets.