Question

During a coordinate bond formation, (a) one electron from an atom is transferred to other (b) one electron each is lost from both the atoms (c) a pair of electrons is contributed by one atom and shared by both the atoms (d) a pair of electrons is transferred to the other atom.

Short answer

(c) A pair of electrons is contributed by one atom and shared by both atoms.

Step-by-step solution

Understanding Coordinate Bond Formation

A coordinate bond, also known as a dative covalent bond, is a type of covalent bond in which both of the shared electrons come from the same atom. In normal covalent bonding, each atom contributes one electron to the bond. However, in a coordinate bond, one atom donates both electrons to the shared pair.

Analyzing the Options

(a) Incorrect, because in a coordinate bond, the electrons are shared, not transferred. (b) Incorrect, because it describes a situation where both atoms lose electrons, which is not the case in coordinate bonding. (d) Incorrect, as the electrons are shared, not transferred.

Determining the Correct Option

(c) is the correct answer. In a coordinate bond formation, one atom donates a pair of electrons that are shared by both atoms. This is the defining characteristic of a coordinate bond.

Key concepts

Dative Covalent Bond

A dative covalent bond, which may be a new term for some students, is essentially a 'friendly loan' of electrons between two atoms. It's a type of bond that's peculiar because, unlike a standard covalent bond where each atom pitches in one electron to form a happy pair, in a dative bond, one atom generously offers up both electrons to create the bond.

Imagine you and a friend want to play catch, but your friend doesn't have a ball. You provide the ball and start the game—this is similar to how a dative covalent bond forms. One atom, playing the generous role, brings an extra pair of electrons (the ball in our analogy) to the bonding game. It's essential for students to understand that despite this kind gesture, the ball is still used by both players. Similarly, both atoms use the electron pair equally once the bond is formed.

In chemistry lingo, we say the atom donating the electrons is the 'donor' and the other atom is the 'acceptor'. This unique bonding process leads to the formation of compounds with various properties and is a key concept in understanding chemical reactions and molecular structures.

Covalent Bonding

Covalent bonding is the bread and butter of many molecules that make up the world around us. It's about sharing and stability. Covalent bonds form when two or more atoms share electrons, trying to achieve a noble gas configuration, which means they want a full outer shell of electrons for maximum happiness (stability).

Atoms are a bit like people at a potluck dinner party. Each one brings something to the table, in this case, one electron. The atoms then share these electrons to enjoy a 'full plate' or a complete outer shell. This sharing fosters a strong bond between the atoms—practically making them partners for life, or at least until a chemical reaction parts them. Such bonds are common in organic compounds, water, and oxygen gas, just to mention a few.

For students to fully understand, imagine two atoms holding hands, each hand representing one electron. They’re holding onto each other, creating a stable unit. This idea of sharing and jointly holding onto the electrons is the central concept of covalent bonding.

Electron Pair Donation

Electron pair donation is a charitable act at the atomic level. It's the core of how a dative covalent bond is born. One atom, the philanthropist of the microscopic world, decides to give away an electron pair to another atom. This isn't just donating for the sake of it, though. There's a method to the atomic madness!

Why would an atom give away precious electrons? The answer lies in achieving stability. Sometimes, an atom has electrons to spare—maybe it has more than it needs to fill its outer shell, or it wants to gain a positive charge. On the flip side, another atom is looking to fill its own shell. When the donor atom steps up, it donates a pair of electrons, allowing them both to reach a more stable and happy state.

Think of an electron pair donation like giving a pair of gloves to someone with cold hands. Your hands are warm, and you have an extra pair of gloves, so you offer them to your friend. This act warms you both because shared warmth improves friendship, just like shared electrons improve atomic relationships.