Answer
metal
Explanation
A)
metalloid
Metalloids have properties intermediate between the metals and nonmetals.
They have low density and will melt at low temperatures. They can be shiny or dull.
B)
nonmetal
Non-metals are very brittle and dull. They have low density (they feel light for their size) and of weak strength
C)
metal
metals are silvery looking, high density and hard in its physical appearance.
D)
lanthanide
The lanthanides have a bright silvery appearance. They are soft, they can be cut with a knife.
