Asample of radioactive waste has a half-life of 10 years and an activity level of 2 curies. after how many years will the activity level of this sample be 0.25 curie? a. 10 yearsb. 20 yearsc. 30 yearsd. 40 yearse. 80 years

c. 30 years

Step-by-step explanation:

The expression for half life of a radioactive substance is given as

λ/λ₁ = 2⁽ᵃ/ᵇ⁾ Equation 1

Where λ₁ =  remaining sample, λ = original sample, a = Total disintegration time, b = half life.

Given: λ = 2 curies, λ₁ = 0.25 curies, b = 10 years.

Substituting these values into equation 1

2/0.25 = 2⁽ᵃ/¹⁰⁾

8 = 2⁽ᵃ/¹⁰⁾

2³ = 2⁽ᵃ/¹⁰⁾

Since the base in both side of the equation is the same, we can equate the base.

3 = a/10

a/10 = 3

a = 10×3

a = 30 years.

Thus it will take 30 years for the activity level of the sample to be 0.25 curie

The right option is c. 30 years

the balance is found at the link

step-by-step explanation:

answer: 140

step-by-step explanation:

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