Question

Given below are the atomic numbers of some group 14 elements. The atomic number of the element with the lowest melting point is:

• A. 14
• B. 6
• C. 82
• D. 50

Hint:

The melting point decreases as we go down group 14, with lead having the lowest melting point.

Answer 1

The Correct Option is D

The question requires us to identify the element from Group 14 of the periodic table that possesses the lowest melting point, based on the given atomic numbers. The atomic numbers listed correspond to specific elements as follows:

• Carbon (C) - Atomic number 6 
• Silicon (Si) - Atomic number 14
• Tin (Sn) - Atomic number 50
• Lead (Pb) - Atomic number 82

Group 14 elements include Carbon, Silicon, Germanium, Tin, and Lead. One distinctive property of these elements is their varying melting points. Generally, upon moving down the group, the melting points tend to decrease with some local exceptions due to structural differences.

Let's compare the melting points based on typical properties of the elements:

• Carbon (C) has a very high melting point as it exists as graphite or diamond.
• Silicon (Si) has a high melting point due to its covalent bonding structure.
• Tin (Sn) exists in several allotropes, one of which, called grey tin, has a low melting point.
• Lead (Pb) has a relatively low melting point but still higher than grey tin.

Among the given elements, Tin has the allotrope with the lowest melting point (especially grey tin, which is metallic and has a lower melting point compared to other elements mentioned).

Thus, the element with the lowest melting point among the given atomic numbers is Tin (Atomic number 50).

Correct Answer: 50

Answer 2

The melting points of group 14 elements generally decrease as we move down the group. The elements with the atomic numbers 6 (carbon), 14 (silicon), 50 (tin), and 82 (lead) have decreasing melting points. Among them, tin (atomic number 50) has the lowest melting point.
Thus, the correct answer is (4) 50.