The number of atoms in 6.5mole of Na are?

Options

A. 25 x `10^23`
B. 39 x `10^23`
C. 35 x `10^23`
D. 48 x `10^23`

Explanation

To find the number of atoms in 6.5 moles of sodium (Na), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the concept of moles**:
- One mole of any substance contains Avogadro's number of entities (atoms, molecules, etc.), which is approximately \(6.02 \times 10^{23}\).

2. **Identify the number of moles**:
- In this problem, we have \(6.5\) moles of sodium.

3. **Calculate the total number of atoms**:
- To find the total number of atoms in \(6.5\) moles of sodium, we multiply the number of moles by Avogadro's number:
\[ \text{Number of atoms} = \text{Number of moles} \times \text{Avogadro's number} \]
\[ \text{Number of atoms} = 6.5 \times 6.02 \times 10^{23} \]

4. **Perform the multiplication**:
- Calculate \(6.5 \times 6.02\):
\[ 6.5 \times 6.02 = 39.13 \]
- Therefore, the total number of atoms is:
\[ 39.13 \times 10^{23} \]

5. **Express the answer in scientific notation**:
- We can express this as approximately:
\[ 3.913 \times 10^{24} \text{ atoms} \]
- Or, rounding it to significant figures, we can write it as:
\[ 39 \times 10^{23} \text{ atoms} \]

### Final Answer:
The number of atoms in 6.5 moles of sodium is approximately \(39 \times 10^{23}\) atoms.