Nuclear & Astrophysics Quiz (Quizgecko) PDF

**[Radioactivity:]** The process in which an unstable atomic nuclei releases an energetic subatomic particle - **Detection of Radiation:** Radiation cannot be detected through our 5 sense: special detectors are required: - - - - - **Geiger müller Tube:** 1. 2. 3. 4. 5. 6....

**[Radioactivity:]** The process in which an unstable atomic nuclei releases an energetic subatomic particle - **Detection of Radiation:** Radiation cannot be detected through our 5 sense: special detectors are required: - - - - - **Geiger müller Tube:** 1. 2. 3. 4. 5. 6. 7. 8. **Three types of radioactive emissions:** **Rule of nuclear radiation:** - - **Alpha particle:** - - - -  **Beta Particle: (β)** - - - - - **Gamma rays: (**Ɣ) - - - - **Deflection of Radiactive emissions in electric field:** Alpha particle: - Beta particle: - Gamma rays: - **Deflection of radioactive emission in magnetic field:**  Alpha particle: - Beta particle: - - Gamma rays: - Summary: Type of radiation Alpha particle Beta particle Gamma rays --------------------------- ------------------------------------------------------------------------------ -------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------- Properties Each particle is 2 protons +2 neutrons (Identical to a helium nucleus) Electrons EM wave similar to X-rays Charge relative to proton +2 -1 0 Ionising effect Strong Weak Very weak Penetrating effect Really low pernetration: blocked by thick paper or a few cm of air particles Mediocre penetration: stopped by a few millimetres of aluminium or other metal Extremly high penetration, never completly stopped: Lead and thick concrete reduce the effect Effect of field Deflected by magnetic field (to south), low deviation Deflected by magnetic field, to north, high deviation No deviation **Radioactive decay:** - - - **Nuclear Equations:** - - **Alpha decay:** - - - **Beta Decay:** - -  **Gamma emission:** - - **Nuclear reactions:** Types of Nuclear reactions: Nuclear fission and fusion **Nuclear fusion:** The process by which multiple atomic nuclei join together to form a heavier nucleus which is accompanied by the release or absorption of energy **Nuclear fission:** The process by which the nucleus of an atom splits into two or more smaller atoms as fission products along with some by products  **Nuclear reactor:** - - Chain reaction: - - **Stars:** - - - **Half life:** The time taken for a radioactive nuclei to deacy to half of its size. Can be also defined as the count rate to fall to half of its initial reading - **Uses of Radioactive isotopes and safety precautions:** - **Precautions:** 1. - 2. - - - 3. - - 4. - **Uses:** **Medical tracer:** - - - **Important:** A radioactive sample with short half-life must be used as a medical tracers, otherwise it would stay in the body and cause harmful effects **Detecting leaks:** - - - **Carbon dating:** A radioisotope called Carbon-14 is present within all organisms, It has a very long half-life. All living things always stay in equlibrium of the carbon-14 present as background radiatiotion till the point of death; it starts to decay with a half life of 5700 years then. Thus we use it to estimate how old samples are based on their half life. This enables us determine the age of things such as fossils. **Disadvantage of Carbon-dating:** - - - Remaining: - - **Astrophysics** Weight: The force acting upon an object with gravitational force. - **Gravitational field strength** The force acting on a unit of mass, each gravitational planet has a different gravitational field strength - **The Solar System** The system that lies in the milky way - - - - -  Note: Pluto's gravitational field is not that strong to orbit the sun **Satilittes:** Celestial objects in space that orbit larger celestial objects in space - - **Asteroids and Comets** *Asteroids*: small rocky objects that orbit the sun *Comets*: celestial objects that are made of dust and ice; when comets get close to the sun, their ice melts to form a comets tail. **The Creation of the Solar system:** - - *Ancient Model of the Solar system (Geocentric model)* - *Heliocentric model* - - **Circular motion:** If the distance from the objects remains the same throughout circular motion Note: Objects with smaller mass shall always orbit objects with bigger mass i)Direction of the object is constantly changing because its in circular motion. Therfore, the velocity also changes ii\) The direction of velocity is determined by the tangent to the circle at that point iii\) The force keeps the object moving in a circular path; this is called centripedial force which is always to the center of the object that its orbiting Note: The speed of circular motion in orbit is greater the closer the object is that its encircling **Life cycle of a Stars:** Stars are kept in balance because of 2 forces: Gravity & outward force due to thermal expansion of gases in the star They're 2 types of stars: **Solar mass stars:** Stars whose size is similar to that of our solar system. They have 5 stages in their life: 1. 2. 3. 4. 5. **Massive Stars:** Stars whose size is much bigger than that of our solar system. 1. 2. 3. 4. 5. 6. **Big Bang Theory:** 1. 2. 3. 4. **Steady State Theory:** 1. 2. **Dopler effect:** The apparent change in the frequency and wavelength in a moving object source relative to the reference source **Galatic RedShift**: The shift of electromagnetic spectral lines readings being concentrated the red end of the spectrum due to galaxies moving furhter away. **Galatic BlueShift:** The shift of electromagnetic spectral lines readings being concentrated the violet end of the spectrum due to galaxies getting closer.