What is Covalency?

S4-SA2-0340

Grade Level:

Class 6

Space Technology, EVs, Climate Change, Biotechnology, HealthTech, Robotics, Chemistry, Physics

Definition

What is it?

Covalency is a way atoms share electrons with each other to become stable. Imagine two friends sharing a single cricket bat so both can play. Similarly, atoms share electrons to fill their outermost electron shells.

Simple Example

Quick Example

Think about how you and your friend might share a single pack of colourful chalk in school. Instead of one person having all the chalk and the other having none, you both use the same set of chalk sticks. This 'sharing' is similar to how atoms share electrons in covalency.

Worked Example

Step-by-Step

Let's understand how a water molecule (H2O) forms using covalency.

1. A Hydrogen atom (H) needs 1 electron to be stable.
---
2. An Oxygen atom (O) needs 2 electrons to be stable.
---
3. One Hydrogen atom shares its 1 electron with the Oxygen atom. Oxygen now has 1 electron from this Hydrogen.
---
4. Another Hydrogen atom shares its 1 electron with the Oxygen atom. Oxygen now has 2 electrons from the two Hydrogens.
---
5. In return, the Oxygen atom shares 1 electron with each Hydrogen atom.
---
6. Now, each Hydrogen atom feels like it has 2 electrons (its own 1 + 1 from Oxygen), becoming stable. The Oxygen atom feels like it has 8 electrons (its own 6 + 1 from each Hydrogen), also becoming stable.
---
7. This sharing of electrons between Hydrogen and Oxygen atoms is covalency, forming a stable water molecule.
---
ANSWER: Water (H2O) is formed by covalent bonds where atoms share electrons.

Why It Matters

Understanding covalency helps us know how molecules are formed, which is crucial in fields like Biotechnology for creating new medicines and in Climate Change research to study atmospheric gases. Scientists and engineers use this knowledge to design materials for Space Technology and develop better batteries for EVs.

Common Mistakes

MISTAKE: Thinking atoms completely give or take electrons in covalency. | CORRECTION: In covalency, atoms SHARE electrons, they don't transfer them fully.

MISTAKE: Believing only one electron is shared between two atoms. | CORRECTION: Atoms can share one, two, or even three pairs of electrons, leading to single, double, or triple covalent bonds.

MISTAKE: Confusing covalency with ionic bonding. | CORRECTION: Covalency involves sharing electrons, while ionic bonding involves the complete transfer of electrons from one atom to another.

Practice Questions

Try It Yourself

QUESTION: If two atoms each contribute one electron to be shared, how many shared electrons are there in total? | ANSWER: 2 shared electrons.

QUESTION: A Carbon atom needs 4 electrons to be stable, and a Hydrogen atom needs 1 electron. How many Hydrogen atoms would typically bond with one Carbon atom using covalency to form a stable molecule? | ANSWER: 4 Hydrogen atoms.

QUESTION: Nitrogen (N) needs 3 electrons to be stable. If two Nitrogen atoms bond with each other, how many pairs of electrons will they share to achieve stability for both? What type of covalent bond is this? | ANSWER: They will share 3 pairs of electrons (6 electrons in total). This is a triple covalent bond.

MCQ

Quick Quiz

What is the main idea behind covalency?

Atoms completely transfer electrons to each other

Atoms share electrons with each other to become stable

Atoms attract each other without exchanging electrons

Atoms become charged by losing protons

The Correct Answer Is:

Covalency is all about atoms sharing electrons to achieve a stable electron configuration. Options A and D describe different types of bonding or atomic changes, not covalency. Option C is incomplete as it doesn't mention electrons.

Real World Connection

In the Real World

Many everyday things around us are held together by covalent bonds. For example, the plastic in your mobile phone case, the sugar in your chai, and even the DNA in your body are all formed by atoms sharing electrons. Understanding this helps chemists at companies like Reliance or Tata develop new materials and pharmaceuticals.

Key Vocabulary

Key Terms

ATOM: The basic unit of matter | ELECTRON: A tiny particle with a negative charge, orbiting the nucleus of an atom | STABLE: When an atom has a full outermost electron shell, making it unreactive | MOLECULE: A group of two or more atoms held together by chemical bonds

What's Next

What to Learn Next

Now that you understand covalency, you can explore 'Ionic Bonding' to see another important way atoms join together. Then, you can learn about 'Molecular Structures' to see how these bonds create amazing shapes and properties in the world around us!