Question

the table shows the physical properties of four elements.

element	luster	conductivity	malleability
selenium	dull	poor conductor of heat or electricity	brittle, breaks easily
potassium	silvery, shiny	conducts heat and electricity	can be shaped into thin sheets
polonium	metallic	semi - conductor of electricity and heat	can somewhat be shaped into sheets

which element is classified as a metalloid?

a titanium

b selenium

c potassium

d polonium

Explanation:

Metalloids have properties between metals and non - metals: semi - conductive, some metallic luster, and moderate malleability. Titanium and Potassium are metals (good conductors, malleable). Selenium is a non - metal (poor conductor, brittle). Polonium is semi - conductive, has metallic luster, and moderate malleability, so it's a metalloid.

Answer:

D. Polonium