The following function [color=#c51414][b]A[/b][/color] [color=#c51414]gives the amount of substance left[/color] after a certain amount of time, x. [br][br]In the applet below, simply enter the i[color=#0a971e]nitial amount of substance (in the green text box)[/color] and the [color=#1551b5]half life of this element (in the blue text box)[/color]. [br][br]Feel free to drag the [color=#c51414]red point[/color] as much as you want.