A chemical substance has a decay rate of 6% per day. The rate of change of an amount N of the chemical after t days is given by= dn/dt =-0.060N a) Let No represent the amount of the substance present at t = 0. Find the exponential function that models the decay. b) Suppose that 300 g of the substance is present at t = 0. How much will remain after 2 days? c) What is the rate of change of the amount of the substance after 2 days? d) After how many days will half of the original 300 g of the substance remain