Can atoms change from one type to another at anytime?

Iwill give extra points to who gets this right

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

What is bromine+calcium iodide--> calcium bromide +iodine balanced