How many `109^(@)28'` bond angles in `CH_(4)` molecules?

Explanation

To determine how many `109° 28'` bond angles are present in a `CH₄` (methane) molecule, we can follow these steps:

### Step 1: Understand the Structure of `CH₄`
`CH₄` consists of one carbon atom bonded to four hydrogen atoms. The carbon atom has four valence electrons, and each hydrogen atom has one valence electron.

### Step 2: Determine the Hybridization
The carbon atom in `CH₄` forms four bonds with hydrogen atoms and has no lone pairs of electrons. The steric number (the number of bonded atoms plus lone pairs) is 4. This indicates that the hybridization of the carbon atom is `sp³`.

### Step 3: Identify the Molecular Geometry
With `sp³` hybridization and a steric number of 4, the molecular geometry of `CH₄` is tetrahedral. In a tetrahedral structure, the bond angles between the hydrogen atoms are all equal.

### Step 4: Calculate the Bond Angles
In a tetrahedral geometry, the bond angles are `109° 28'`. Since there are four hydrogen atoms bonded to the carbon atom, we can visualize the angles formed between each pair of hydrogen atoms.

### Step 5: Count the Number of `109° 28'` Bond Angles
In the `CH₄` molecule, there are multiple pairs of hydrogen atoms that form angles of `109° 28'`. Specifically, we can identify the following angles:
1. H1-H2-H3
2. H1-H2-H4
3. H1-H3-H4
4. H2-H3-H4

Each of these pairs of hydrogen atoms forms a bond angle of `109° 28'`. Therefore, there are a total of **6 bond angles** of `109° 28'` in the `CH₄` molecule.

### Final Answer
Thus, the number of `109° 28'` bond angles in a `CH₄` molecule is **6**.

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