DRAW:
One water molecule
Label all atoms
Label all polar covalent bonds
Label all partial charges
DRAW:
Two water molecules
Attached to each other by hydrogen bond
Label hydrogen bonds
The Correct Answer and Explanation is:
Here is a drawing and explanation of one water molecule and two water molecules forming a hydrogen bond, along with labels for atoms, polar covalent bonds, partial charges, and hydrogen bonds.
✅ DRAWING: One Water Molecule (H₂O)
δ− δ+ δ+
O —— H H
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Polar covalent bonds- Atoms labeled:
- O = Oxygen (δ−)
- H = Hydrogen (δ+)
- Partial charges:
- Oxygen: δ− (partially negative)
- Hydrogen: δ+ (partially positive)
- Bonds:
- Two polar covalent bonds between O and H
✅ DRAWING: Two Water Molecules with Hydrogen Bond
δ− δ+ δ− δ+
O —— H H ························· H —— O —— H
| / |
Polar covalent bonds Polar covalent bonds
↑
Hydrogen bond (between O of one molecule and H of another)- Hydrogen bond shown as dotted line: ········
- Between: O (δ−) of one molecule and H (δ+) of the other
📘 Explanation
A water molecule (H₂O) consists of one oxygen atom covalently bonded to two hydrogen atoms. The O-H bonds are polar covalent because oxygen is more electronegative than hydrogen, pulling the shared electrons closer to itself. As a result, the oxygen atom gains a partial negative charge (δ−) and each hydrogen atom gains a partial positive charge (δ+).
The geometry of a water molecule is bent (angular) with a bond angle of approximately 104.5°, caused by the two lone pairs on the oxygen which repel the bonded pairs of electrons.
This polarity leads to intermolecular hydrogen bonding, a key feature of water. When multiple water molecules are present, the partially positive hydrogen atom of one molecule is attracted to the partially negative oxygen atom of another molecule. This attraction is called a hydrogen bond, represented by a dotted line.
Hydrogen bonds are weaker than covalent bonds but crucial for many of water’s unique properties, such as:
- High boiling point
- Surface tension
- Cohesion and adhesion
- Ice being less dense than liquid water
Hydrogen bonding plays an essential role in biological systems as well, such as the structure of DNA and protein folding.
In summary, each water molecule forms polar covalent bonds internally, and hydrogen bonds externally with other water molecules. The combination of these bond types gives water its remarkable chemical and physical behavior.
