According to the periodic table, how many elements are metalloids?
Despite the lack of an agreed definition of the term "metalloid", the most commonly accepted are six.
Thing with "metalloids", is that their definition is not completely agreed upon to have a clear and defined list of them.
The most general definition would be "metalloids are elements with properties that fall between metals and non-metals, or a mixture of both". However, not everyone agrees completely upon this. The six mainly accepted metalloids are boron, silicon, germanium, arsenic, antimony, and tellurium.
However, carbon, aluminium, selenium, polonium, and astatine are also added into the them by some, totaling up to 11 metalloids.
I hope that answers your question.