Starting with 100 grams of uranium-238, after one half life has gone by, how many grams of uranium-238 will remain?

50 grams

To answer this question, we need to understand the concept of a half-life. The half-life of a radioactive substance is the time it takes for half of the substance to decay or break down. In the case of uranium-238, its half-life is approximately 4.5 billion years.

To calculate the remaining grams of uranium-238 after one half-life, we can use the formula:

Remaining amount = Initial amount × (1/2)^(number of half-lives)

In this case, we have an initial amount of 100 grams and we want to find the amount after one half-life. So, let's plug in the values into the formula:

Remaining amount = 100 grams × (1/2)^(1)

Calculating (1/2)^(1) = 1/2, we get:

Remaining amount = 100 grams × 1/2 = 100 grams / 2 = 50 grams

Therefore, after one half-life has gone by, there will be 50 grams of uranium-238 remaining.