The number of atoms in 0.4mole of Na are?

Options

A. 1.4 x `10 ^23`
B. 2.4 x `10 ^23`
C. 1.4 x `10 ^24`
D. 2.4 x `10 ^24`

Explanation

To find the number of atoms in 0.4 moles of sodium (Na), we can follow these steps:

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

### Step 2: Identify the number of moles given
In this case, we are given 0.4 moles of sodium (Na).

### Step 3: Use Avogadro's number to calculate the number of atoms
To find the total number of atoms in 0.4 moles of sodium, we can use the formula:
\[ \text{Number of atoms} = \text{Number of moles} \times \text{Avogadro's number} \]
Substituting the values:
\[ \text{Number of atoms} = 0.4 \, \text{moles} \times 6.02 \times 10^{23} \, \text{atoms/mole} \]

### Step 4: Perform the multiplication
Calculating the above expression:
\[ \text{Number of atoms} = 0.4 \times 6.02 \times 10^{23} = 2.408 \times 10^{23} \, \text{atoms} \]
Rounding this to two significant figures gives us:
\[ \text{Number of atoms} \approx 2.4 \times 10^{23} \, \text{atoms} \]

### Final Answer
The number of atoms in 0.4 moles of sodium is \(2.4 \times 10^{23}\) atoms.

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