why does covalent bonding involve metalloids and non metals but not metals?

Question

I know it’s pretty basic but I just can’t wrap my hear around any of the explanations in my textbook/google

In: 20

Answer 1

covalent bonding does involve metals. lithium and beryllium tend to form covalent bonds than ionic ones. they’re charge to radius ratio is too high for them to let go of their valence electrons so they share electrons.

BeCl2 is an example. this way Be is electron deficient in its orbit because it needs to fill an orbital after covalently bonding so it joins with another such molecule to fullfill it’s orbit to become stable.

Al is also covalent in some sorts. it forms a trihalide and then dimerizes (2 molecules join, as above) to satisfy aluminium’s electron deficiency. it’s tricky with such metals because they tend to form bonds of covalent nature, because of their charge to radius ratio. as you go down, it decreases and so does the covalent character and tendency to form bonds having some amount of this nature.