Answer:
1 × 10⁸ He atoms
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
I would say A. Because it looks as though it’s the best answer
Answer: Elements in the same column are similar in their properties
Explanation: The columns on the periodic table are also know as group of the periodic table elements in the same group of the periodic table tends to have similar chemical properties because they all have the same number of valence electrons in their outermost shell. This plays an important roles in their reactivity and properties
It’s the water method that helps it