1. What is Amount of Substance Left After Three Half Lives?

Definition: This calculator determines the remaining amount of a radioactive substance after it has undergone three half-life periods.

Purpose: It helps in nuclear physics, radiochemistry, and medical applications to understand radioactive decay processes.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( N_t(3) \) — Amount of substance left after three half-lives (kg)
• \( N_0 \) — Initial concentration of radioactive substance (kg)

Explanation: After each half-life, the amount of substance is halved. After three half-lives, it's reduced to 1/8th of the original amount.

3. Importance of Half-Life Calculations

Details: Understanding radioactive decay helps in determining safe handling procedures, storage requirements, and medical dosage calculations.

4. Using the Calculator

Tips: Enter the initial concentration of the radioactive substance in kilograms. The value must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why does the amount reduce to 1/8th after three half-lives?
A: Each half-life reduces the amount by half: 1/2 after first, 1/4 after second, and 1/8 after third half-life.

Q2: What's a typical half-life duration?
A: Half-lives vary greatly - from fractions of a second to billions of years, depending on the isotope.

Q3: Does this calculation account for all decay products?
A: No, it only calculates the remaining parent substance, not any daughter products.

Q4: How precise should my initial concentration measurement be?
A: For radioactive materials, extremely precise measurements are often needed due to the small quantities involved.

Q5: Can this be used for dating purposes?
A: Yes, knowing the remaining amount and half-life allows calculation of elapsed time since formation.