Fill in the blanks in the following graph, which illustrates the decay curve of a radioactive element used to date fossil structures.

Verified step by step guidance

1. Step 1: Observe the graph provided. The y-axis represents the 'Percentage of remaining radioactive material,' while the x-axis represents the 'Number of half-lives.' The decay curve shows how the percentage of radioactive material decreases over time.
2. Step 2: Identify the point on the graph where the percentage of remaining material is 25%. This corresponds to the y-axis value of 25%. Trace horizontally from this point to the decay curve, then vertically down to the x-axis to determine the number of half-lives.
3. Step 3: Recall the concept of half-life. A half-life is the time it takes for half of the radioactive material to decay. After one half-life, 50% remains; after two half-lives, 25% remains. This pattern continues, halving the remaining material with each half-life.
4. Step 4: Using the graph, confirm that 25% remaining corresponds to two half-lives. This means the radioactive material has undergone two cycles of decay, reducing its original amount to one-quarter.
5. Step 5: Fill in the blanks: 'Using this decay curve, we can see that a value of 25% remaining on the y-axis corresponds to 2 times the number of half-lives.'

Key Concepts

Radioactive Decay

Radioactive decay is the process by which an unstable atomic nucleus loses energy by emitting radiation. This decay occurs at a predictable rate, characterized by the half-life, which is the time required for half of the radioactive atoms in a sample to decay. Understanding this concept is crucial for interpreting decay curves, as they visually represent the decrease in the quantity of a radioactive substance over time.

Half-Life

Half-life is a key concept in radioactive decay that defines the time it takes for half of a given amount of a radioactive substance to decay into a more stable form. For example, if a sample has a half-life of 1,000 years, after 1,000 years, only half of the original amount will remain. This concept is essential for dating fossils, as it allows scientists to estimate the age of a sample based on the remaining percentage of the radioactive isotope.

Decay Curve

A decay curve is a graphical representation of the decrease in the quantity of a radioactive substance over time. The y-axis typically shows the percentage of the substance remaining, while the x-axis represents time or the number of half-lives that have passed. Analyzing the decay curve helps in determining the age of fossils by identifying how much of the radioactive material remains, which can be correlated to the time elapsed since the organism's death.