Question

The diameter of a helium atom is about 1 3 102 pm. Suppose that we could line up helium atoms side by side in contact with one another. Approximately how many atoms would it take to make the distance from end to end 1 cm

Answer 1

1 × 10⁸ He atoms

Step-by-step explanation:

Step 1: Given data

• Diameter of a helium atom (d): 1 × 10² pm

• Total distance to be covered (D): 1 cm

Step 2: Convert "d" to meters

We will use the conversion factor 1 m = 10¹² pm.

1 × 10² pm × (1 m / 10¹² pm) = 1 × 10⁻¹⁰ m

Step 3: Convert "D" to meters

We will use the conversion factor 1 m = 100 cm.

1 cm × (1 m / 100 cm) = 0.01 m

Step 4: Calculate the number of atoms of He required

We will use the following expression.

D/d = 0.01 m / 1 × 10⁻¹⁰ m = 1 × 10⁸