Question

Which of the following has the highest melting point?
A. Magnesium
B. Barium
C. Calcium
D. Beryllium

Answer 1

Hint: periodic table is a great source of information about the elements and their relation to each other. Changes of different periodic properties. Also, this helps to predict the properties of the elements even if they are not discovered. Beryllium, magnesium, calcium, barium is from group 2. Which is on the left side of the periodic table.

Complete step by step answer:
To answer this question the periodic properties of the elements from the different groups should be known. The periodic properties have opposite trends between left to right and top to bottom. The elements in periodic tables are arranged in a way that every element of each group shows similar physical characteristics and chemical characteristics.
In the case of the periodic table from left to right metallic character decreases and non-metallic character increases as well as the electropositivity of the element decreases and electronegativity increases.
As metals are electropositive, they tend to donate electrons. And as non-metals are electronegative, they tend to accept electrons.
Among the group 2 elements top to bottom the size increases as a result the metal-metal bond becomes weaker. In the case of beryllium due to the small size, the metal-metal bond is very strong. As a result, the bond strength of beryllium is highest among the group 2 elements. So, the melting point of beryllium is highest.

So, the correct option is D.

Note:According to periodic properties of the elements of the second period (Li, B, Be) and third period (Mg, Al, Si) elements which are diagonally present with each other in the periodic table, show some similar kind of chemical properties. For example, the formation of nitrides, halides. this kind of similarity of their properties is called diagonal relationship.