should i put metal roof over shingles
Non-metals and metals do not always gain or lose electrons in either case. The exact definitions are debatable between scholars. Check several sources for a definition and see which one you like best. If you are in a class, then I suggest that you only see what your textbook says.
One of the defining characteristics of a metal is the fact that its atoms form metallic bonds. In this type of bonding, unlike covalent and ionic bonding, the valence electrons become completely delocalized, or completely removed from any host atom or bond, and form a sea of electrons around the metal atoms. This is part of why metals tend to be malleable, shiny, and good conductors, among other properties.
Metals have 1-3 electrons in the outer shell of each atom. Non metals usually have 4-8 electrons in their outer shell.
Metals are electropositive elements that usually have a shiny surface, are generally good conductors of heat and electricity, and can be melted or fused, hammered into thin sheets, or drawn into wires. Typical metals form salts with nonmetals, basic oxides with oxygen, and alloys with one another. Aloha
Metals are on the left side of the periodic table and the non-metals on the right.
