3) Rn-222 is the most stable isotope of radon. If it takes 9.74 days for a sample of Rn-222 to decay to 17%
of its initial mass, what is the half-life of Rn-222?

Calculate the estimated density of each ball. use the formula d = m/v where d is the density, m is the mass, and v is the volume. record your calculations in table a of your student guide. given that the density of water is 1.0 g/cm3, make a prediction about whether each ball will float in water. record your prediction in table a. what is the estimated density of the table tennis ball? record your answer to the nearest hundredth