Answer:
Ionic bond.
Step-by-step explanation:
An element which has just one or two electrons in its outermost shell or valence shell will be able to lose the one or two electrons easily and can achieve noble gas configuration. So they form positive ions. Now these positive ions can easily form ionic bond with negative ions (which have accepted the electrons and hence gains negative charge).
For example sodium has only one electron in its valence shell and hence it can easily lose it to attain Neon gas configuration.