Calculate the number of neutrons in the remaining atoms after the emission of an alpha particle from `._(92)U^(238)` atom.

Explanation

To calculate the number of neutrons in the remaining atoms after the emission of an alpha particle from a Uranium-238 atom, we can follow these steps:

### Step 1: Understand the initial atom
The initial atom is Uranium-238, represented as \( _{92}^{238}U \). Here, the atomic number (92) indicates the number of protons, and the mass number (238) is the total number of protons and neutrons.

### Step 2: Identify the alpha particle
An alpha particle is represented as \( _{2}^{4}He \). It consists of 2 protons and 2 neutrons, which means it has a mass number of 4.

### Step 3: Determine the new element after alpha emission
When an alpha particle is emitted from Uranium-238, the atomic number and mass number of the original atom change:
- The atomic number decreases by 2 (because 2 protons are lost).
- The mass number decreases by 4 (because 2 protons and 2 neutrons are lost).

### Step 4: Calculate the new atomic number and mass number
- New atomic number: \( 92 - 2 = 90 \)
- New mass number: \( 238 - 4 = 234 \)

Thus, the new element formed is \( _{90}^{234}Th \) (Thorium-234).

### Step 5: Calculate the number of neutrons in the new element
The number of neutrons can be calculated using the formula:
\[ \text{Number of neutrons} = \text{Mass number} - \text{Atomic number} \]
Substituting the values:
\[ \text{Number of neutrons} = 234 - 90 = 144 \]

### Final Answer
The number of neutrons in the remaining atoms after the emission of an alpha particle from Uranium-238 is **144**.

---