Question

Name the metalloid in the carbon family.
a) Carbon
b) Tin
c) Silicon
d) Lead

Answer 1

Hint: Metallic character as we move down the group. As a result of this, the carbon group contains one non-metal, two metalloids and two metals. With these hints in mind, try and eliminate the options which are inappropriate.

Complete step-by-step answer:
Let us first define what a metalloid really is so as to ensure that there are no misunderstandings later on.
A metalloid is an element that has properties that are intermediate between those of metals and non-metals. Metalloids can also be called semimetals. On the periodic table, the elements coloured yellow, which generally border the stair-step line, are considered to be metalloids. Notice that aluminium borders the line, but it is considered to be a metal since all of its properties are like those of metals.
Now lets us look at the Carbon family and the trend of metallicity that is observed in it from top to bottom.
As you move down the periodic table in the carbon family, the atomic radius and ionic radius increase while electronegativity and ionization energy decrease. Atom size increases moving down the group because an additional electron shell is added.
Element density increases moving down the group.
The carbon family consists of one non-metal (carbon), two metalloids (silicon and germanium), and two metals (tin and lead). In other words, the elements gain metallicity moving down the group.
Silicon is a typical metalloid. It has lustre like a metal, but is brittle like a nonmetal. Silicon is used extensively in computer chips and other electronics because its electrical conductivity is in between that of a metal and a nonmetal.
Therefore, by our above analysis, we can safely conclude that the answer is c) Silicon

Note: As it possesses a valency of 4 and due to other properties like its size and electron gain enthalpy, Silicon is very flexible in its chemical reactions and can either gain/lose four electrons to fill its valence shell. This is the major reason behind Si being classed as a metalloid.