A radioactive substance has an initial mass of 600 grams and...

Question Analysis
This question tests the student's ability to write the function expression for exponential decay. The problem provides the initial mass and the decay factor.

Key Concept Explanation
In an exponential decay function , the base is a fraction between 0 and 1.

Step-by-step Solution
1. Identify the initial mass grams.
2. Determine the decay factor