Home > CAAC > Chapter 13 > Lesson 13.OF2-S > Problem 7-146
7-146.
Half-life means time in which half of the original 50 grams will remain.
y = abn
a is the initial value,
b is the multiplier (0.5 since we are working with a half-life),
n is the number of thousands of years, and
y is the amount of the isotope that remains (in grams).
The equation is y = 50(0.5)x. Substitute 10 for x.
Use the equation below, where x is the number of years.
Use the equation from the help for part (a).
In this case, y = 1% of 50 and you are solving for x.
≈ 6600 years
