A certain radioactive element has a half life of 1 h. If you start with a 1-g sample of the element at noon, how much is left at 3:00 PM? At 6:00PM? At 10:00 PM?
1.0 g/2n = ??
where n is the number of half lives.
1/23 = 1/8 g or 0.125
The others are done the same way.
i have no idea
To find out how much of the radioactive element is left at different times, you need to understand the concept of half-life and use the formula for calculating the amount remaining.
The half-life of a radioactive element is the time it takes for half of a sample to decay. In this case, the half-life is given as 1 hour. This means that after every hour, the amount of the element remaining will be halved.
To calculate the amount left at a specific time, you can use the formula:
Amount Remaining = Initial Amount x (0.5)^(Time / Half-life)
Let's calculate the amount remaining at different times:
1. From noon to 3:00 PM: The time elapsed is 3 hours.
Amount Remaining = 1g x (0.5)^(3 / 1) = 1g x 0.5^3 = 1g x 0.125 = 0.125g.
Therefore, at 3:00 PM, 0.125 grams of the radioactive element is left.
2. From noon to 6:00 PM: The time elapsed is 6 hours.
Amount Remaining = 1g x (0.5)^(6 / 1) = 1g x 0.5^6 = 1g x 0.015625 = 0.015625g.
Therefore, at 6:00 PM, 0.015625 grams of the radioactive element is left.
3. From noon to 10:00 PM: The time elapsed is 10 hours.
Amount Remaining = 1g x (0.5)^(10 / 1) = 1g x 0.5^10 = 1g x 0.0009765625 = 0.0009765625g.
Therefore, at 10:00 PM, 0.0009765625 grams of the radioactive element is left.
Using the formula and the given half-life, you can calculate the remaining amount for any given time.