Final answer:
To calculate the percent decrease in volume when a potassium atom becomes a potassium ion, use the volume of a sphere formula and then find the percent change. The respective volumes are calculated using the given radii, and the decrease is approximately 76.66%.
Step-by-step explanation:
The student is asking how to calculate the percent decrease in volume when a potassium atom (K) becomes a potassium ion (K+). To find the percent decrease in volume, you must first calculate the volumes of both the atom and the ion using the formula for the volume of a sphere, V = (4/3)πr3, where r is the radius.
The volume of the K atom: VK = (4/3)π(216 pm)3
The volume of the K+ ion: VK+ = (4/3)π(133 pm)3
To find the percent decrease, subtract the final volume from the initial volume, divide by the initial volume, and multiply by 100.
Percent decrease in volume (%) = ((VK - VK+) / VK) × 100
Substituting the values and calculating gives a percent decrease of approximately 76.66%.