Hole

1. Jasmine and William each owned a box called B-box. Each box contained B gas molecules which are represented in blue. Each B molecule moves independently in a random manner and is able to escape through a hole in the box. B molecule Hole Escaping B molecules B-box

2. Jasmine and her B-Box Jasmine had 800 million B molecules in her B-box initially. She noticed that it took 1 minute for the quantity of B molecules in her box to decrease from 800 million to 760 million. 1 minute 800 million molecules 760 million molecules

3. William and his B-Box William had 2000 million B molecules in his B-box initially. William’s B-box was similar to Jasmine’s box in every way except for the initial number of B molecules present in the box. 2000 million molecules initially William’s B-box 800 million molecules initially Jasmine’s B-box

4. William’s Prediction Based on Jasmine’s results, the number of B molecules in my B-box will decrease by 40 million from 2000 million to 1960 million after 1 minute.

5. William’s Prediction vs Actual Results To William’s shock and dismay, the number of molecules in his B-box actually decreased by 100 million from 2000 million to 1900 million after 1 minute. Actual Result Predicted Result 1 minute 1960 million molecules 1900 million molecules 2000 million molecules

6. Jasmine’s result in the second minute William took a closer look at Jasmine’s results and realized that for the second minute, the B molecules in Jasmine’s B-box decreased to 722million. 1 minute 1 minute 722 million molecules 800 million molecules 760 million molecules

7. Your Challenge for the day • Explain why B molecules in William’s B-box decreased by 100 million after 1 minute. • From your explanation, predict how B molecules in Jasmine’s and William’s boxes will decrease in subsequent minutes. • Identify some patterns or characteristics in the way B molecules decreases. • Hence, predict the outcome in practical situations where a similar type of change occurs.