Calcium bonds with oxygen through an ionic bond, a chemical bond formed by the transfer of electrons between atoms.
When calcium (Ca) bonds with oxygen (O), it forms calcium oxide (CaO), a compound held together by strong electrostatic forces. This process involves the complete transfer of electrons from the calcium atom to the oxygen atom.
The Electron Transfer Process
The formation of the ionic bond between calcium and oxygen occurs as follows:
- Calcium Atom (Ca): A calcium atom is in Group 2 of the periodic table, meaning it has two valence electrons in its outermost shell. To achieve a stable electron configuration, similar to that of a noble gas, the calcium atom readily donates these two valence electrons.
- Oxygen Atom (O): An oxygen atom, located in Group 16, has six valence electrons. To complete its outer shell and attain a stable octet, it needs two more electrons.
As per the reference, in this ionic bond, the calcium atom donates two of its valence electrons to the oxygen atom to form a calcium cation and oxygen anion.
This electron transfer results in the formation of charged ions:
- Calcium Cation (Ca²⁺): After losing two electrons, the calcium atom becomes a positively charged ion with a +2 charge, known as a cation. Its electron configuration now resembles that of Argon.
- Oxygen Anion (O²⁻): After gaining two electrons from calcium, the oxygen atom becomes a negatively charged ion with a -2 charge, known as an anion. Its electron configuration now resembles that of Neon.
Achieving Electrical Neutrality
Since an oxygen atom has 2 valence electrons, it can accept both valence electrons from the calcium atom leading to a net charge of 0 for the ionic compound. The equal and opposite charges of the calcium cation (+2) and the oxygen anion (-2) perfectly balance each other, resulting in a neutral ionic compound, calcium oxide (CaO).
Summary of Electron Transfer
The table below summarizes the electron exchange and the resulting ions:
| Atom | Initial Valence Electrons | Electrons Transferred | Resulting Ion | Charge |
|---|---|---|---|---|
| Calcium | 2 | Loses 2 | Calcium Cation | +2 |
| Oxygen | 6 | Gains 2 | Oxygen Anion | -2 |
This strong electrostatic attraction between the positively charged calcium ions and the negatively charged oxygen ions forms the stable ionic lattice structure characteristic of calcium oxide.
