It's the bottom one. 20 dollars has to be less than or equal to the amount. you cannot spend more than $20
Answer:
Step-by-step explanation:
As an example, iodine-131 is a radioisotope with a half-life of 8 days. It decays by beta particle emission into xenon-131. After eight days have passed, half of the atoms of any sample of iodine-131 will have decayed, and the sample will now be 50% iodine-131 and 50% xenon-131.
50 grams to 25 grams is one half-life. 25 grams to 12.5 grams is another half-life. So, for 50 grams to decay to 12.5 grams, two half-lives, which would take 36 days total, would need to pass. This means each half-life for element X is 18 days.
Essentially look at your formula sheets, Take notes on your assessment questions and you should be fine.
Answer:
5
Step-by-step explanation:
Answer:
2565 square ft
Step-by-step explanation:
675 x 3.8 = 2565 square feet
