Ch. 10 – Chemistry – Flashcards
Flashcard maker : Kael Dunlap
Radioactivity
unstable nucleus emits charged particles or energy or both
gamma decay
nuclear decay releases energy but not a particle
half the sample decay
half life of an radioisotope
True
chemical reaction rates vary with the conditions of the reaction, but nuclear decay rates do not
uranium-235
radioisotope used to date rock formations
An alpha particle is the same as a___ nucleus
helium
234/91 PA —> 234/92 U + __?___
a beta particle
A sample of uranium-235 is heated from room temperature to 55 C. How will increasing the temperature of the sample affect the half-life of the isotope?
temp doesn’t affect speed of reaction, so it doesn’t affect the half-life
In terms of forces, when does a nucleus become radioactive?
strong nuclear force can’t overcome electric forces
Use the equation E=mc2 to explain why large amounts of energy are produced by very small amounts of mass during fission.
energy produced is mass times the speed of light.
– so since multiplied it makes more energy
– so since multiplied it makes more energy
Write a balanced equation for the beta decay of protactinium-234
234/91 Pu —-> 0/-1 e 234/92 U
What radioactive isotope undergoes alpha decay to produce radium-226?
230/90 Th —-> 4/2 He + 226/88 Ra
You have 600 atoms in a sample. How many atoms remain after 1 half-life? 3 half-lives?
1st = 300
3rd = 75
3rd = 75
Compare/contrast fission and fussion
REFER TO YOUR NOTES!!!
radioisotopes are used for medical testing, do they have short or long half-lives?
Short….limits the patient’s exposure to radiation.
