Atomic and Nuclear Physics Flashcards
Atom
The smallest part of an element that can exist on its own
Charge
The property that causes electrical effects
Plum pudding model 🧁
Negative electrons spread throughout the atom like currents in a bun - positive charge that we spread throughout the atom 🧁
Observations for Rutherford nuclear experiment
- most of the particles went straight through the foil
- A few alpha particles were slightly deflected
- Some were deflected through very large angles
- 1 in 8000 were “back scattered”
radioactivity
radioactivity is the process that occurs when alpha particles, beta particles or gamma waves are emitted from an unstable nucleus
alpha particles
the helium nuclei containing two protons and two neutrons which are emitted by radioactive nuclei
beta particles
beta particles are fast-moving electrons emitted by radioactive nuclei
gamma radiation
gamma radiation is a high-energy electromagnetic wave emitted by radioactive nuclei
Nature of alpha particle
Each particle is two protons, and two neutrons nucleus of helium – 4
Source of alpha particles
A radioactive nucleus
Relative charge of an alpha particle compared with charge on proton
+2
Mass of alpha particle compared with beta
High
Speed of alpha particle
Up to 0.1 x speed of light
Ionising effect of alpha particle
Strong 💪
Penetrating effect of alpha particle
Very low penetrating power, stopped by a few cms of air or thin tissue paper
Nature of beta particle
A fast electron
Source of beta particle
A radioactive nucleus
Beta particle relative charge compared with the charge on a proton
–1
Beta particle mass
Low
Speed of beta particle
Around 10% the speed of light
Ionising effect of beta particle
Weak
Penetrating Effect of beta particle
Penetrating but stopped by a few millimetres of aluminium or other metal
Nature of Gamma rays
Very high-energy electromagnetic waves
Source of gamma rays
A radioactive nucleus
Relative charge of gamma rays compared to charge on proton
0
Mass of gamma rays
0
Speed of gamma rays
Speed of light
Ionising effect of gamma rays
Very weak
Penetrating effect of gamma rays
Very .Never completely stopped although lead and thick concrete will reduce intensity
Background activity
Comes from natural sources, e.g cosmic rays from space, rocks and soil
How is radioactive material passed along the food chain?
Living things and plants absorb radioactive material from the soil, which are than passed along the food chain
How does human behaviour add to background activity?
- Medical x-rays 🩻
- radioactive waste from nuclear power plants ☢️ 🌱
- radioactive fallout from nuclear weapons testing 🕳️ 🏃♀️
Background radiation
All natural sources of radiation
Examples of background radiation
- Inside our bodies 🫁
- Radioactive elements in Food, potassium 🍌
- certain rocks contain uranium
- Cosmic rays
What are all isotopes of uranium?
Radioactive
What do all isotopes of uranium decay to give?
Radon, a radioactive gas
Nuclear fission
The process of uranium nucleus absorbing a slow electron, and then splitting to produce two or more lighter nuclei and several neutrons together with a vast quantity of energy
What causes nuclear fission?
Are you uranium nucleus is struck by a slow neutron
Controlled nuclear fission
Steps are taken a nuclear power stations to ensure that on average, just one of the fission neutrons goes on to produce further fission
What can nuclear energy do?
Produces vast amounts of energy/electricity
How does nuclear energy not contribute to global warming?
Produces very little CO2
What produces the “base-load” for national electricity generation?
Nuclear energy
What is a high- density source of energy?
Nuclear energy
What provides employment opportunities for many people?
Nuclear energy
What are many nations planning on building?
More nuclear reactors 🏭
