In chemical bonding, a bond formed mainly by complete transfer of one or more electrons from one atom to another is known as which type of bond?

Introduction / Context:
Atoms can join together through different types of chemical bonds depending on how they share or transfer electrons. One very important class of bond involves one atom losing electrons and another atom gaining those electrons, resulting in oppositely charged ions that attract each other. This question asks you to name the type of bond that is formed predominantly by the transfer of electrons between atoms, a foundational concept in chemical bonding and ionic compounds.

Given Data / Assumptions:

• The bond described involves transfer, not sharing, of electrons.
• One atom becomes positively charged and the other becomes negatively charged.
• Options include ionic, covalent, co-ordinate, hydrogen, and metallic bonds.
• We assume standard definitions from introductory chemistry.

Concept / Approach:
When an atom of a metal with low ionisation energy transfers an electron to a non metal atom with high electron affinity, a cation and an anion are formed. The electrostatic attraction between these oppositely charged ions constitutes an ionic bond. In contrast, covalent bonds involve sharing electron pairs between atoms, co-ordinate bonds involve a shared pair donated entirely by one atom, hydrogen bonds are weak intermolecular attractions, and metallic bonds involve a lattice of positive ions in a sea of delocalised electrons. Therefore, the bond formed mainly by transfer of electrons is called an ionic bond.

Step-by-Step Solution:
Step 1: Identify key words in the question, such as "transfer of electrons" and "between atoms of the elements". Step 2: Recall that in ionic bonding, one atom loses electrons to become a cation and another gains electrons to become an anion. Step 3: Recognise that the resulting electrostatic attraction between these oppositely charged ions is what we call an ionic bond. Step 4: Contrast this with covalent bonding, where electrons are shared rather than completely transferred. Step 5: Note that co-ordinate, hydrogen, and metallic bonds all involve different mechanisms and do not fit the simple transfer description given in the question.

Verification / Alternative check:
Take a common example such as sodium chloride. A sodium atom loses one electron to form Na plus, and a chlorine atom gains one electron to form Cl minus. The bond between Na plus and Cl minus is purely electrostatic and is described as ionic. The process clearly involves electron transfer rather than sharing. By contrast, in a chlorine molecule Cl2, each atom shares one electron pair in a covalent bond. In ammonia, nitrogen shares electrons with hydrogen in covalent bonds. None of these examples contradict the definition that transfer of electrons leads to ionic bonding.

Why Other Options Are Wrong:
A covalent bond is formed by sharing of electron pairs between atoms, so it does not involve complete transfer. A co-ordinate bond is a special case of covalent bond where one atom donates both electrons in the shared pair, but again the electrons are shared, not fully transferred. A hydrogen bond is a weak attraction between a hydrogen atom already covalently bonded to an electronegative atom and another electronegative atom nearby; it is not a primary electron transfer bond. A metallic bond is the attraction between metal cations and a sea of delocalised electrons in a metal lattice. None of these fit the phrase "formed by transfer of electrons" as precisely as an ionic bond.

Common Pitfalls:
Students sometimes confuse ionic and covalent bonds because both involve valence electrons and can appear together in complex compounds. Another mistake is to think that co-ordinate bonding is somehow more "ionic" because one atom donates electrons, but it is still a shared pair. To avoid confusion, remember the key distinction: in ionic bonding, electrons are completely transferred, creating ions; in covalent and co-ordinate bonding, electrons are shared. Focus on the word "transfer" in the question to quickly identify the bond as ionic.

Final Answer:
A bond formed mainly by transfer of electrons from one atom to another is called an ionic bond.