You have 480 grams of a radioactive kind of samarium. If its half-life is 90 years,
how much will be left after 180 years?

120 grams will be left after 180 years.

Step-by-step explanation:

A radioactive half-life refers to the amount of time it takes for half of the original isotope to decay and its given by

where,

= quantity of the substance remaining

= initial quantity of the substance

= time elapsed

= half life of the substance

From the information given we know that:

And we want to find how much will be left. For this we use the above formula.

120 grams will be left after 180 years.

x = ± 6i

step-by-step explanation:

x^2 = -36

take the square root of each side

sqrt(x^2) = sqrt(-36)

we know sqrt(ab) = sqrt(a) sqrt(b)

x = ±sqrt(36) sqrt(-1)

we know that sqrt (-1) = i

x = ± 6i

whats the