Radioactivity Overview

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Who identified radioactivity and shared the Nobel Prize in 1903?

  • Wilhelm Röntgen
  • Albert Einstein
  • Henri Becquerel (correct)
  • Marie and Pierre Curie

What is the charge of a positron, a type of beta particle?

  • -1
  • +1 (correct)
  • +2
  • 0

Which type of radiation has no mass or charge?

  • Beta
  • Gamma (correct)
  • Electron
  • Alpha

How does the half-life of a radioactive isotope relate to its decay?

<p>It is the time required for half of the isotopes to decay. (C)</p> Signup and view all the answers

Which detection tool is specifically designed to measure radiation quantitatively?

<p>Scintillation Counter (B)</p> Signup and view all the answers

Which radiation type is the least penetrating and can be stopped by paper?

<p>Alpha (B)</p> Signup and view all the answers

What is the consequence of radiation exposure at 600 rem?

<p>Lethal dose within one month (D)</p> Signup and view all the answers

Which of the following is a stable isotope characteristic?

<p>264 naturally occurring isotopes are stable. (C)</p> Signup and view all the answers

Flashcards

Radioactivity

The spontaneous emission of particles or energy from the nucleus of an unstable atom.

Alpha decay

The emission of an alpha particle (helium nucleus) from an unstable nucleus, decreasing atomic number by 2 and mass number by 4.

Beta decay

A type of radioactive decay in which a neutron changes into a proton and emits an electron.

Gamma decay

The emission of high-energy electromagnetic radiation (gamma rays) from an unstable nucleus, without any change in atomic or mass number.

Signup and view all the flashcards

Half-life

The time it takes for half of a radioactive sample to decay.

Signup and view all the flashcards

Stable isotope

An isotope that does not undergo radioactive decay.

Signup and view all the flashcards

Radiation sickness

A set of symptoms that can appear after a large dose of ionizing radiation.

Signup and view all the flashcards

Radiation Dosimetry

The measurement of radiation exposure and its potential effects.

Signup and view all the flashcards

Study Notes

Radioactivity

  • Key figures in the discovery of radioactivity include Wilhelm Röntgen (X-rays), Henri Becquerel (identified radioactivity in 1896), and Marie and Pierre Curie (named the phenomenon and shared the 1903 Nobel Prize)
  • Radioactivity is the phenomenon of the spontaneous emission of radiation

Types of Radiation

  • Alpha (α): Helium nuclei (2 protons, 2 neutrons), carrying a +2 charge
  • Beta (β): Electrons with a -1 charge or positrons (β+) with a +1 charge
  • Gamma (γ): High-energy electromagnetic radiation; no mass or charge

Radioactivity Details

  • Wavelength and frequency (λ and ν) are inversely related (λ=c/ν).
  • Gamma rays have high energy and are invisible to the human eye.

Nuclear Radiation

  • Stable isotopes (264 naturally occurring types of stable isotopes).
  • Radioactivity in isotopes with imbalance in proton-to-neutron ratio.
  • Types of decay
    • Beta Emission: Neutron turns into a proton and an ejected electron
    • Alpha Emission: Helium nucleus ejection reducing atomic number by 2 and mass number by 4.
    • Positron Emission: Proton turns into a neutron and an ejected positron
    • Gamma Emission: High energy state -> ground state, no change in atomic/mass numbers
    • Electron Capture: Nucleus captures an electron reducing atomic number by 1.

Half-Life

  • Time taken for half of a radioactive sample to decay
  • Examples: Iodine-131 decays via beta and gamma emissions.

Measuring Radioactivity

  • Detection tools to measure radiation exposure
    • Dosimeters
    • Geiger counters
    • Scintillation counters

Penetration Power

  • Alpha: Least penetrating, stopped by paper
  • Beta: Penetrates paper, stopped by thin lead
  • Gamma: Highly penetrating, stopped by thick lead

Radiation Dosimetry

  • Effects of radiation exposure
    • 25 rem: Whole-body exposure, noticeable in blood count
    • 100 rem: Symptoms of radiation sickness
    • 400 rem: Death within a month in 50% of exposed individuals
    • 600 rem: Almost always fatal within a month
    • 50,000 rem: Required to kill bacteria
    • 1,000,000 rem (10^6 rem): Required to inactivate viruses
  • 100 rem: Radiation sickness
  • 600 rem: Lethal dose within a month

Nuclear Medicine

  • Use of radionuclides for diagnosis and treatment

Nuclear Fusion

  • Process: Fusing light nuclei (e.g., hydrogen) into heavier ones (e.g., helium).
  • Applications: Energy source in stars and creation of transuranium elements

Nuclear Fission

  • Process: Splitting heavy nuclei (e.g., Uranium-235) into smaller ones, releasing energy.
  • Applications: Controlled nuclear reactors and uncontrolled nuclear weapons
  • Waste Management: Spent fuel disposal at sites like Yucca Mountain

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

More Like This

Física Nuclear: Conceptos Fundamentales
5 questions
Chemistry Concepts and Radioactivity
5 questions
Radioactivity and Radiation Types Quiz
25 questions
Physics Concepts: Radioactivity and Sound
13 questions
Use Quizgecko on...
Browser
Browser