metalloid + non- metal 係咩bond? (ionic/covalent)?

metalloid and non-metal form covalent compounds. the metalloid have mainly non-metal characters.
the above sample SiO2 is very special, it is giant covalent compound. one Si atom bond with 4 oxygen atom, and one O atom bond with 2 Si atom, and it structure of it is like a network.

covalent bond
只有metal+non-metal?metalloid先會係ionic bond
好似鹽咁...
鹽係NaCl
sodium係metal, chlorine係non-metal
所以鹽係ionic bond

covalent
例如SiO2
SiCl4 都係covalent compound