The correct option is D.
Isotopic substances typically have unstable nuclei and that is why they disintegrate in order to become stable. During the process of disintegration, the nucleus of the unstable substance will be split into two smaller fragments, which are more stable that the parent isotope. This disintegration may also be accompanied by radiations.
False. Newton first is also called the law of intertia
it's either the first or second choice
