Answer:
Substitutional alloys tend to be more ductile than interstitial alloys. true
Interstitial alloys tend to form between elements with similar ionic radii.false
Nonmetallic elements are never found in alloys. false
Explanation:
Substitutional alloys consists components having similar atomic(ionic) radii as well as common bonding characteristics. In interstitial alloys, atoms in interstitial positions must have a much smaller covalent radius than the solvent atoms. Interstitial atoms are generally less ductile than substitutional alloys.
Nonmetals are found in alloys. For instance, carbon is a component of the common alloy called steel.