The question requires us to choose the best option regarding the bonds of nonmetal atoms.
Nonmetal atoms can form different types of bonds depending on the atom they are bonding to. They can participate in ionic bonds, where electrons are donated or received (exchanged electrons), usually when bonded to a metal (in this case, the metal usually "loses" the electron, while the nonmetal "gains" the electrons). They can also form covalent bonds when the electrons are shared with other nonmetals.
Regarding the options provided by the question, we can make the following comments:
- 1st option: the type of bond described, where electrons can move freely, is typical of metallic bonding;
- 2nd option: gaining electrons describe ionic bonding, while sharing electrons is related to covalent bonding;
- 3rd option: noble gases are the atoms with full valence orbitals.
- 4th option: losing valence electrons is also a description of ionic bonding.
Considering the information above, the best option to answer the question is the second one:
"Nonmetal atoms form bonds by gaining or sharing electrons".
(nonmetals participate in ionic bonds by donating electrons and in covalent bonds by sharing electrons).