How many electron domains are around the central atom ina water molecule?
To determine the number of electron domains around the central atom in a water molecule, you need to first understand the concept of electron domains.
An electron domain refers to any region in which electrons are likely to be found. This includes both lone pairs of electrons and bonded electron pairs. Electron domains can be found around the central atom of a molecule, and they help in determining its molecular shape.
Now, let's consider a water molecule (H2O) specifically. Water consists of two hydrogen atoms bonded to a central oxygen atom.
To determine the number of electron domains around the central oxygen atom, follow these steps:
1. Identify the total number of valence electrons for all the atoms in the molecule and add them up. In the case of water, oxygen has 6 valence electrons, and each hydrogen has 1 valence electron. So, we have 6 (from oxygen) + 1 (from each hydrogen) + 1 (from each hydrogen) = 8 valence electrons.
2. Distribute the valence electrons around the central atom and the bonded atoms using a Lewis structure. In the Lewis structure for water, oxygen will act as the central atom, with two hydrogen atoms bonded to it. Each oxygen-hydrogen bond will consist of a single pair of electrons.
H H
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H - O - H
Hydrogen atoms each require one electron to complete their valence shell, while oxygen requires two electrons. Therefore, in the Lewis structure, the oxygen atom will have two lone pairs of electrons.
3. Count the total number of electron domains around the central atom. In the case of water, count the number of lone pairs and the number of bonded pairs to determine the total electron domains.
In water, there are two lone pairs of electrons around the central oxygen atom and two bonded pairs. Therefore, the total number of electron domains around the central atom in a water molecule is four.
To summarize, in a water molecule (H2O), the central oxygen atom is surrounded by four electron domains: two lone pairs of electrons and two bonded pairs.