what are the properties of the latter mentioned?
Physically, they largely exist as diatomic or monatomic gases while chemically they mostly have high ionisation energies.
Nonmetal
Physically, they largely exist as diatomic or monatomic gases
what is metalloid? It is a type of chemical element. what are the isotopes of this element? UNANSWERABLE what is its description? It is a  mixture of metals and nonmetals.
wiki:8306020
Nonmetal [SEP] Properties
Nonmetals show more variability in their properties than do metals. These properties are largely determined by the interatomic bonding strengths and molecular structures of the nonmetals involved, both of which are subject to variation as the number of valence electrons in each nonmetal varies. Metals, in contrast, have more homogenous structures and their properties are more easily reconciled. Physically, they largely exist as diatomic or monatomic gases, with the remainder having more substantial (open-packed) forms, unlike metals, which are nearly all solid and close-packed. If solid, they have a submetallic appearance (with the exception of sulfur) and are mostly brittle, as opposed to metals, which are lustrous, and generally ductile or malleable; they usually have lower densities than metals; are mostly poorer conductors of heat and electricity; and tend to have significantly lower melting points and boiling points than those of metals.