Electrons. The particle name doesn't change just because it is a free electron. Free at last!
Yes, free electrons can collide with atoms.
conduction
Atoms that have lost electrons are positive ions, and are called cations.
Electrons in metallic bonds are called "delocalized electrons", which means they exist in an atoms orbitals, but are extended over multiple atoms. It is often called a "sea of electrons" because the electrons are free to "roam" between atoms, and is what gives metal the ability to conduct electricity.See related links below for more information.
Hot gases containing charged and uncharged atoms and free electrons is plasma.
No. Atoms have the same number of protons and electrons. When atoms gain or lose electrons they are called ions.
insulators do not have free electrons
Metals have "free" electrons, the free electrons in metals help to transfer heat together with the vibrating atoms.
Free electrons in a metal are called delocalized.
The electrons in the outermost shell is called as valence electron. These electrons are free and they are involved in bonding reactions.
If atoms lose electrons they will have a positively charged ion called a cation. If they gain electrons, they will have a negatively charged ion called an anion.
These are the valence electrons.