Physics Unit 1
- Created by: Chipandaxxx
- Created on: 09-03-16 08:44
View mindmap
- Physics Unit 1
- Atomic structure
- Atom has a positively charged nucleus surrounded by negatively charged electrons
- Protons and neutrons are called nucleons
- Isotopes are atoms with the same number of protons and diffident number of neutrons
- A = Mass or nucleon number
- Z = Atomic or proton number
- Uncharged atoms have equals numbers of protons no electrons
- A nuclide is a type of nucleus with a particular number of protons and neutrons
- Specific charge = charge ÷ (nucleon x electron mass)
- The election has the highest specific charge out of all the other particles
- The higher the neutron : proton ratio the more unstable the nucleus is
- The strong nuclear force is an attractive force between nucleons that holds them in the nucleus
- A range of no more than 3-4 fm
- Same effect between al nucleons
- Below a separation of 0.5 fm it is a repulsive force
- To prevent nucleons from being pushed into each other
- Alpha radiation consists of alpha particles (2 protons, 2 neutrons)
- Beta radiation consists of fast moving electrons
- Gamma radiation is electromagnetic radiation emitted by an unstable nucleus
- Carries away excess energy
- Beta minus decay produces an antineutrino
- Beta plus decay produces a neutrino
- Gamma radiation is electromagnetic radiation emitted by an unstable nucleus
- Beta radiation consists of fast moving electrons
- Wavelength of electromagnetic radiation ? = c ÷ f
- Electric wave and magnetic wave travel together and vibrate perpendicularly and in phase
- A charged particle emits EM waves when it loses energy
- Eg. When a fast moving electron slows down or changes direction or when an electron moves to a lower energy level in an atom
- Emitted burst of EM waves are called photons
- A photon has an energy if E = hf
- The power of a beam of photon = nhf where n is the number of photons passing a point per second
- A photon has an energy if E = hf
- A charged particle emits EM waves when it loses energy
- Electric wave and magnetic wave travel together and vibrate perpendicularly and in phase
- antiparticles annihilate their corresponding particles when they meet
- They have the same rest mass as the particle and opposite charge
- Annihilation produces two photons (mass is converted to energy)
- Min energy of each photon = hf = E?
- For pair production a photon needs an energy hf = 2E?
- Min energy of each photon = hf = E?
- Atomic structure
Comments
No comments have yet been made