True/False: Atoms of the same elements have different properties

Iknow #2 is d. i just need to know why

What happens to the atomic radius when an elctron is lost

2pos suppose an object in free fall is dropped from a building. its starting velocity is 0 m/s. ignoring the effects of air resistance, what is the speed (in m/s) of the object after falling 3 seconds? give your answer as a positive decimal without units. answer here