The plutonium isotope 239 Pu has a half-life of 24,000 years and decays by the emission of a 5.2 MeV alpha particle. Plutonium is not especially dangerous if handled because the activity is low and the alpha radiation doesn’t penetrate the skin. However, there are serious health concerns if even the tiniest particles of plutonium are inhaled and lodge deep in the lungs. This could happen following any kind of fire or explosion that disperses plutonium as dust. Let’s determine the level of danger.
The unstable nuclei undergo radioactive decay. We can predict the decay pattern. the number of left(N)
Here the number of atoms at the time
Stars are powered by nuclear reactions that fuse hydrogen into helium. The fate of many stars, once most of the hydrogen is used up, is to collapse, under gravitational pull, into a neutron star. The force of gravity becomes so large that protons and electrons are fused into neutrons in the reaction . The entire star is then a tightly packed ball of neutrons with the density of nuclear matter.
a. Suppose the sun collapses into a neutron star. What will its radius be? Give your answer in .
b. The sun's rotation period is now 27 days. What will its rotation period be after it collapses?
Rapidly rotating neutron stars emit pulses of radio waves at the rotation frequency and are known as pulsars.
The fact that A cancels means that all nuclei have this density. It is a staggeringly large density, roughly 1014 times larger than the density of familiar liquids and solids. One early objection to Rutherford’s model of a nuclear atom was that matter simply couldn’t have a density this high. Although we have no direct experience with such matter, nuclear matter really is this dense .
94% of StudySmarter users get better grades.Sign up for free