Which pair of atoms contains the same number of neutrons?

Options

A. `""_(48) ^(112) Cd` and `""_(50)^(119) Sn`
B. `""_(27) ^(59) Co` and `""_(26)^(56) Fe`
C. `""_(55) ^(133) Cs` and `""_(54)^(131) Xe`
D. `""_(29)^(64) Cu` and `""_(30)^(65) Zn`

Explanation

To determine which pair of atoms contains the same number of neutrons, we can follow these steps:

### Step 1: Understand the Concept
Neutrons in an atom can be calculated using the formula:
\[ \text{Number of Neutrons} = \text{Mass Number} - \text{Atomic Number} \]

### Step 2: Analyze Each Option
We will evaluate each option provided to find the pair of atoms with the same number of neutrons.

#### Option A:
- **C (Carbon)**:
- Mass Number = 12
- Atomic Number = 6
- Neutrons = 12 - 6 = 6
- **Sn (Tin)**:
- Mass Number = 119
- Atomic Number = 50
- Neutrons = 119 - 50 = 69
- **Conclusion**: Not the same.

#### Option B:
- **Fe (Iron)**:
- Mass Number = 56
- Atomic Number = 26
- Neutrons = 56 - 26 = 30
- **Another Atom**: (not specified in the transcript)
- **Conclusion**: Cannot determine without the second atom.

#### Option C:
- **I (Iodine)**:
- Mass Number = 133
- Atomic Number = 53
- Neutrons = 133 - 53 = 80
- **Xe (Xenon)**:
- Mass Number = 131
- Atomic Number = 54
- Neutrons = 131 - 54 = 77
- **Conclusion**: Not the same.

#### Option D:
- **Cu (Copper)**:
- Mass Number = 64
- Atomic Number = 29
- Neutrons = 64 - 29 = 35
- **Zn (Zinc)**:
- Mass Number = 65
- Atomic Number = 30
- Neutrons = 65 - 30 = 35
- **Conclusion**: Both have 35 neutrons.

### Step 3: Final Answer
The pair of atoms that contains the same number of neutrons is **Copper (Cu) and Zinc (Zn)**, both having **35 neutrons**.