A radioactive element decays according to the function y = y e - 0.01281 , where a. y = grams yo is the amount present initially and t is the time in years (Type an integer or a decimal Round to three decimal places as needed.) a. If there are 10 grams of the element present today, how much will be present in 50 years? b. The half-life is approximately | years (Type an integer or a decimal. b. Use the graph of the function to approximate how long it will take for 20 grams Round to the nearest tenth as needed.) to decay to 10 grams, 10 grams to decay to 5 grams, and 5 grams to decay to 2.5 grams. The length of time is called the half-life. In general, a half-life is the time c. The decay factor is b = required for half of a radioactive substance to decay (Type an integer or a decimal Round to four decimal places as needed.) c. Identify the annual decay rate and the decay factor The annual decay rate is 1% (Type an integer or a decimal. Round to two decimal places as needed )