Atomic number of an element is 30 and its atomic weight is 65 . The number of protons and neutrons are

Options

A. 30 and 65
B. 35 and 30
C. 35 and 65
D. 30 and 35

Answer

To solve the problem, we need to determine the number of protons and neutrons in an element with an atomic number of 30 and an atomic weight of 65.

### Step-by-Step Solution:

1. **Identify the Atomic Number**:
The atomic number (Z) is given as 30. The atomic number represents the number of protons in an atom.
\[ \text{Number of Protons} = \text{Atomic Number} = 30 \]

2. **Identify the Atomic Weight**:
The atomic weight (or atomic mass) is given as 65. The atomic weight is the sum of the number of protons and neutrons in the nucleus of an atom.
\[ \text{Atomic Weight} = \text{Number of Protons} + \text{Number of Neutrons} \]

3. **Set Up the Equation**:
We can express the relationship between atomic weight, number of protons, and number of neutrons as follows:
\[ \text{Atomic Weight} = \text{Number of Protons} + \text{Number of Neutrons} \]
Substituting the known values:
\[ 65 = 30 + \text{Number of Neutrons} \]

4. **Solve for the Number of Neutrons**:
To find the number of neutrons, we rearrange the equation:
\[ \text{Number of Neutrons} = 65 - 30 \]
\[ \text{Number of Neutrons} = 35 \]

5. **Final Answer**:
Therefore, the number of protons is 30 and the number of neutrons is 35.
\[ \text{Number of Protons} = 30, \quad \text{Number of Neutrons} = 35 \]

### Summary:
- Number of Protons: 30
- Number of Neutrons: 35