Which of the following is a metalloid?
Metalloids lie along the metal-non-metal boundary. Si (group 14) is a metalloid, while Na (group 1), Mg (group 2), and S (group 16) are not.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Periodic Trends - Atomic Radii Ionic Radii and Ionization Enthalpy