Fullerenes and Allotropes of Carbon

Questions and Answers

What is the key characteristic of allotropes of the same element?

They have different physical states

They have different arrangements of covalent bonds (correct)

They have different valencies

They have different atomic masses

What is the shape of the molecule of buckminsterfullerene?

Both b and c (correct)

Hollow sphere

Closed mesh

Ellipsoid

What is the main reason why carbon can form many allotropes?

Due to its high valency (correct)

Due to its ability to form strong covalent bonds

Due to its low reactivity

Due to its high atomic mass

In what year were fullerenes first discovered?

1985 Signup and view all the answers

What is the term for fullerenes with an open mesh structure?

Nanotubes Signup and view all the answers

What is the process by which fullerenes were first created?

Vaporizing carbon in a helium atmosphere Signup and view all the answers

What was the atmosphere used to create fullerenes?

Helium Signup and view all the answers

What does the 'ene' ending in the formula Cn indicate?

That the carbons are unsaturated Signup and view all the answers

What was observed in the mass spectrum of the product?

Discrete peaks corresponding to molecules with the exact mass of sixty or seventy or more carbon atoms Signup and view all the answers

What is the empirical formula used to denote fullerenes with a closed mesh topology?

Cn Signup and view all the answers

How many carbon atoms were found in the first observed fullerenes?

Sixty or seventy Signup and view all the answers

Study Notes

Allotropes of Carbon

Allotropes are different structural forms of the same element in the same physical state.
Carbon atoms are joined by strong covalent bonds in all allotropes, but with different arrangements.
Carbon can form many allotropes due to its valency.

Fullerenes

Fullerenes are allotropes of carbon with molecules consisting of carbon atoms connected by single and double bonds.
These bonds form a closed or partially closed mesh with fused rings of four to seven atoms.
Fullerenes can have various shapes and sizes, including hollow spheres, ellipsoids, and tubes.

Types of Fullerenes

Fullerenes are categorized as open and closed mesh.
Open mesh fullerenes are in the form of nanotubes.
Closed mesh fullerenes are in the form of 'buckyballs', such as buckminsterfullerene.

Discovery of C60

In 1985, Harold Kroto, James R. Heath, Sean O'Brien, Robert Curl, and Richard Smalley discovered fullerenes.
The discovery was made by vaporizing carbon in a helium atmosphere and analyzing the sooty residue.
The mass spectrum of the residue revealed the presence of fullerenes.

Discovery of Fullerenes

In 1985, Harold Kroto, James R. Heath, Sean O'Brien, Robert Curl, and Richard Smalley discovered fullerenes while vaporizing carbon in a helium atmosphere at the University of Sussex and Rice University.
The discovery was made by analyzing the sooty residue created during the vaporization process.

Characteristics of Fullerenes

Fullerenes are molecules with a closed mesh topology, denoted by their empirical formula Cn.
They have a unique property where carbon atoms are unsaturated, being connected to only three other atoms instead of the normal four.
The name "fullerene" comes from the shortened form of the original name, which was chosen to indicate the unsaturated carbon atoms.

Types of Fullerenes

C60 and C70 are two examples of fullerenes, consisting of sixty and seventy carbon atoms, respectively.
These fullerenes were identified by their discrete peaks in the mass spectrum of the product, corresponding to their exact mass.

Description

This quiz covers the different structural forms of carbon, known as allotropes, and focuses on fullerenes, a type of allotrope with unique molecular structures. Learn about the properties and valency of carbon that enable it to form various allotropes.