Question

The table illustrates the decay occurring in a 352-gram sample of vanadium-49 as time progresses.
Table:
Time (days) | Vanadium-49 (grams)
0 | 352
330 | 176
660 | 88
990 | 44
1,320 | X
Approximately how many grams of vanadium-49 will remain after a span of 1,320 days?
A. 22
B. 11
C. 32
D. 43

Answer 1

To determine the amount of vanadium-49 remaining after 1,320 days, we can observe the pattern in the decay amounts provided in the table.

From the table:

- At 0 days, there are 352 grams.
- At 330 days, there are 176 grams (which is half of 352 grams).
- At 660 days, there are 88 grams (which is half of 176 grams).
- At 990 days, there are 44 grams (which is half of 88 grams).

From this pattern, we see that each time period of 330 days results in the amount of vanadium-49 being halved.

Following this pattern:

- At 0 days: \( 352 \) grams
- At 330 days: \( 352 \div 2 = 176 \) grams
- At 660 days: \( 176 \div 2 = 88 \) grams
- At 990 days: \( 88 \div 2 = 44 \) grams
- At 1,320 days: \( 44 \div 2 = 22 \) grams

Thus, after 1,320 days, there will be approximately 22 grams of vanadium-49 remaining.

The answer is **A. 22**.