Number of protons, neutrons and electrons in the element `._89^231 Y` is.

Options

A. 89,89,242
B. 89,71,89
C. 89,142,89
D. 89,231,89

Answer

To determine the number of protons, neutrons, and electrons in the element denoted as \( _{89}^{231}Y \), we can follow these steps:

### Step 1: Identify the Atomic Number and Mass Number
The notation \( _{Z}^{A}Y \) indicates:
- \( A \) (the mass number) = 231
- \( Z \) (the atomic number) = 89

### Step 2: Determine the Number of Protons
The atomic number \( Z \) represents the number of protons in the nucleus of the atom. Therefore:
- Number of protons = 89

### Step 3: Determine the Number of Electrons
In a neutral atom, the number of electrons is equal to the number of protons. Thus:
- Number of electrons = 89

### Step 4: Calculate the Number of Neutrons
The number of neutrons can be calculated using the formula:
\[ \text{Number of neutrons} = \text{Mass number} - \text{Atomic number} = A - Z \]
Substituting the known values:
\[ \text{Number of neutrons} = 231 - 89 = 142 \]

### Final Summary
- Number of protons = 89
- Number of neutrons = 142
- Number of electrons = 89