Carbon: Forms and Applications

Definition

Carbon is a nonmetal element that forms the basis of all known life on Earth. It is a tetravalent element, meaning it can form four covalent bonds. Allotropes are different structural forms of the same element, and carbon exhibits several fascinating allotropes, each with unique properties.

Explanation

Carbon’s ability to bond in various ways gives rise to a wide array of allotropes. The most well-known are diamond, graphite, and buckminsterfullerene (also known as a buckyball). These allotropes differ due to the arrangements of carbon atoms in their structures.

• Diamond: Carbon atoms are arranged in a rigid, three-dimensional tetrahedral lattice. This strong bonding results in diamond’s exceptional hardness and high refractive index.
• Graphite: Carbon atoms are arranged in layers of hexagonal rings. Weak Van der Waals forces hold the layers together, allowing them to slide past each other, giving graphite its lubricating properties.
• Buckminsterfullerene (C₆₀): Carbon atoms are arranged in a spherical shape, resembling a soccer ball. This unique structure gives buckminsterfullerene interesting electrical and chemical properties.

Core Principles and Formulae

Bonding: Carbon forms covalent bonds. The type of bonding (single, double, or triple) and the arrangement of these bonds define the properties of the allotrope. The hybridized orbitals determine the bond angles and shapes.

Key Formulae:

• Diamond: Pure carbon (C) with a tetrahedral crystal structure.
• Graphite: Pure carbon (C) with a hexagonal layered structure.
• Buckminsterfullerene: C₆₀, an example of a fullerene.

Examples

Diamond: Used in jewelry, cutting tools, and industrial abrasives due to its hardness.

Graphite: Used in pencil leads, lubricants, and electrodes due to its softness and conductivity.

Buckminsterfullerene: Currently being researched for applications in medicine, electronics, and materials science due to its unique shape and properties.

Common Misconceptions

Misconception: All carbon allotropes are hard like diamond.

Reality: Graphite is soft and used as a lubricant. The properties depend on the bonding and structure, not simply that the substance is composed of carbon.

Misconception: Carbon is only found in black forms.

Reality: Diamond is transparent and colorless (though it can have impurities that result in color). The color depends on the arrangement and interactions of light with the atoms.

Importance in Real Life

Carbon is essential to life. Carbon allotropes have numerous applications:

• Diamonds: Jewelry, industrial cutting tools.
• Graphite: Pencil leads, lubricants, electrodes in batteries.
• Activated Carbon: Used in water filters and air purifiers to remove impurities.
• Carbon Fiber: Lightweight and strong material used in aerospace, sports equipment, and automobiles.
• Fullerenes (Buckminsterfullerene, etc.): Potential applications in nanotechnology, drug delivery, and materials science.

Fun Fact

Diamond is formed under extreme pressure and temperature deep within the Earth. The hardest known naturally occurring mineral, it takes billions of years to form.

History or Discovery

Diamond: Known for thousands of years, with its value recognized early on for its beauty and hardness.

Graphite: Discovered in the sixteenth century, initially mistaken for lead. Its use in pencils revolutionized writing.

Buckminsterfullerene: Discovered in 1985 by Robert Curl, Harold Kroto, and Richard Smalley, who won the Nobel Prize in Chemistry in 1996 for their work. Their initial work was based on the observation of carbon atoms in interstellar dust.

FAQs

Q: What is the difference between an allotrope and an isotope?

A: Allotropes are different structural forms of the same element, while isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.

Q: What are some other allotropes of carbon?

A: Besides the commonly discussed ones, other allotropes include nanotubes, graphene, and amorphous carbon (e.g., charcoal, soot).

Q: How are diamonds made?

A: Natural diamonds form under intense pressure and temperature in the Earth’s mantle. Synthetic diamonds are created in laboratories using high-pressure/high-temperature (HPHT) or chemical vapor deposition (CVD) methods.

Recommended YouTube Videos for Deeper Understanding

Q.1 A book is resting on a table. Which of Newton’s laws of motion best explains why the book remains at rest?

Check Solution

Ans: A

Newton’s First Law states that an object at rest stays at rest unless acted upon by a force.

Q.2 A 10 kg box is pushed across a frictionless surface with a force of 20 N. What is the acceleration of the box?

Check Solution

Ans: B

Using Newton’s Second Law, $F = ma$. Therefore, $a = F/m = 20 N / 10 kg = 2 m/s^2$.

Q.3 A rocket is propelled forward by expelling exhaust gases downward. Which of Newton’s laws of motion is primarily responsible for the rocket’s motion?

Check Solution

Ans: C

Newton’s Third Law explains this; for every action, there is an equal and opposite reaction. The rocket exerts a force on the gas, and the gas exerts a force on the rocket.

Q.4 A car of mass 1000 kg accelerates from rest to 20 m/s in 5 seconds. What is the net force acting on the car?

Check Solution

Ans: A

First find acceleration, $a = (v_f – v_i)/t = (20 m/s – 0 m/s) / 5 s = 4 m/s^2$. Then, $F = ma = (1000 kg)(4 m/s^2) = 4000 N$.

Q.5 A ball is thrown upwards. Ignoring air resistance, which of the following statements is true regarding the ball’s motion at the highest point?

Check Solution

Ans: C

At the highest point, the ball momentarily stops, so its velocity is zero. However, gravity still acts on it, causing a non-zero net force and acceleration.

Next Topic: Covalent Bonding in Carbon: Bonds & Structure

Practice: Class 10 Science Extra Questions