Question

Which of the following contains only one element?
A. Marble
B. Diamond
C. Glass
D. Sand

Answer 1

Hint: Diamond is the hardest substance and an allotrope of carbon. Glass is a non-crystalline, fine amorphous solid. Marble is a type of rock composed of carbonate minerals and sand is made up of finely divided rock and mineral particles.

Complete Step by Step Solution:
We have to find out which of the following is made up of one element.
A. Marble
It is a rock of calcium-magnesium carbonate that has undergone recrystallization under the effect of heat, pressure, and aqueous solutions. So, it is not composed of only one element.
So, A is incorrect.

B. Diamond
When a chemical element has two or more distinct forms in a single physical state, they exhibit allotropy. The various physical forms of an element are called its allotropes. The allotropes are attached in different ways but include the same element. Diamond is an allotrope of carbon and contains only carbon. The carbon atoms are connected through strong covalent bonds. Due to the increased stability of the covalent bonds, diamonds are the toughest substance on earth.
So, B is correct.

C. Glass
Glass is a transparent amorphous solid that has overall beneficial technical, and decorative benefits. For example, windows, tableware, and optics. Saleable glasses are composed of silicon dioxide, calcium carbonate, and sodium carbonate. So, it is not composed of only one element.
So, C is incorrect.

D. Sand
Sand is composed of finely spread-out rock and mineral particles. The extensively common component of sand is silicon dioxide, typically in the form of quartz. Quartz has chemical inactivity and significant hardness. So, sand is composed of only one element.
So, D is incorrect.
So, option B is correct.

Note: Carbon has many allotropes and diamond is one of them. It is the unadulterated form of carbon. It is a rigid three-dimensional polymer comprising a considerable number of tetrahedrally set up carbon atoms.