Problem #3: Os-182 has a half-life of 21.5 hours. How many grams of a 10.0 gram sample would have decayed after exactly three half-lives? Solution: (1/2) 3 = 0.125 (the amount remaining after 3 half-lives)
Chemistry questions and answers. A radioactive element has a half-life of 2.1 hours. How many hours will it take for the number of atoms present to decay to one-sixteenth of the initial value? 8.4 0.20 34 21 17.OK, you think to yourself, maybe Valve really is within hours of finishing the five-year, $40 million odyssey that is Half-Life 2's development. Either that or Newell is sure good at building up
In this case, the half-life of this drug is nine hours, so it will reach about 6% of steady state levels in 36 hours: One half-life: 50% drug left, time = Nine hours. Two half-lives: 25% drug left, time = 18 hours. Three half-lives: 12.5% drug left, time = 27 hours. Four half-lives: 6.25% drug left, time = 36 hours.
2. Now, we need to find out how many half-lives have passed in 36 hours. Since the half-life is 7 hours, we can divide 36 hours by 7 hours/half-life to find the number of half-lives: 36 hours / 7 hours/half-life = 36/7 half-lives. Step 3/5 3. To find the remaining mass of the substance after 36/7 half-lives, we can use the formula: Final mass
exactly one-half. The symbol for half -life is T 1/2. Example 1 . Drug A has a half-life of 2 hours. If the initial plasma level of the drug, given as a single dose, is 1200mg/L, what will its plasma level be after 8 hours? Method =2half. −life 600 ÷ 300𝑚𝑚/𝐿 6hr = 3 half −life = 300 ÷ 2 = 150𝑚𝑚/𝐿
If the "half-life" of the exponential decay is 3.5 hours, will the soup cool below the Danger Zone in less than six hours? Show Answer The cooling period of six hours is almost long enough for two "half-lifes" of 3.5 hours each, which would reduce the temperature from 140°F to 70°F to 35°F.
1lGS. how many hours is half life 2
