The half-life of an element is about 16 days. There are 4.3 grams present initially. a. Express the amount of the element remaining as a function of time t. b. When will there be 1 gram remaining? a. Let A(t) be an expression for the amount of the element remaining as a function of time t. Let t be in number of days. What is the expression for the amount of the element remaining as a function of time t? A(t)=