In covalency

Options

A. transfer of electrons takes place
B. one atom acts as donor and other acts as acceptor
C. the electrons are shared by only one atom
D. equal sharing of electrons takes place between two atoms.

Answer

### Step-by-Step Solution:

1. **Understanding Covalency**: Covalency refers to the number of covalent bonds an atom can form, which is determined by the number of electrons it can share with other atoms.

2. **Formation of Covalent Bonds**: A covalent bond is formed when two atoms share one or more pairs of electrons. For instance, in a diatomic molecule like F2 (fluorine gas), each fluorine atom has 7 valence electrons.

3. **Electron Sharing in F2**: In the case of F2, each fluorine atom shares one of its valence electrons with the other. This sharing allows both atoms to achieve a stable electron configuration (8 electrons in their outer shell, following the octet rule).

4. **Evaluating Options**:
- **Option A**: "Transfer of electron takes place" - This is incorrect because covalent bonding involves sharing, not transferring.
- **Option B**: "One atom acts as donor and other acts as acceptor" - This is also incorrect as there is no donor or acceptor; both atoms share equally.
- **Option C**: "Electrons are shared by only one atom" - This is incorrect because both atoms participate in the sharing of electrons.
- **Option D**: "Equal sharing of electrons takes place between two atoms" - This is the correct option as it accurately describes the nature of covalent bonding.

5. **Conclusion**: The best description of covalency is that it involves the equal sharing of electrons between two atoms.