of course they did
no
No, atoms do not physically touch each other because they are surrounded by electron clouds that repel each other due to electromagnetic forces.
Gas particles do not touch each other in the way that solid particles do. The particles in a gas are in constant motion and are separated by large distances relative to their size. However, they can collide with each other and with the walls of their container.
yes perpendicular lines are at right angles to each other. Therefore they have to touch eventually
Planets cannot physically touch because they are separated by the vacuum of space. If by "touch" you mean collide, it would result in a catastrophic event, causing massive destruction and potentially leading to the formation of a new celestial body or disrupting the orbits of other nearby planets.
Perpendicular lines intersect each other at 90 degrees but parallel lines never touch each other
No, parallel actually means that the lines will never touch or cross
No, but they will break up into small parts to make other planets
Of course we will. But shall we?
http://nineplanets.org/ is the best site I have ever found regarding planets. I use it extensively teaching 8th grade Astronomy.
Some people believe that spaceships from other planets have visited Earth, but no one has ever been able to prove it.
no. no humans have ever been to any of the other planets.