AQA GCSE Changes in atoms and EM Waves(Physics)
Changes to atoms and EM Waves
Atoms can absorb or emit electromagnetic waves.
Atoms Absorbing Electromagnetic waves
When an atom absorbs Electromagnetic waves it will cause an electron to move from a lower energy level to a higher energy level.
In the diagram below you can see that the electron has moved from the second energy level to the third energy level
Atoms Emitting Electromagnetic Waves
If an electron moves from a higher energy level to a lower energy level, it will cause the atom to emit electromagnetic waves.
In the diagram below the electron in the 3rd energy level moves down the second energy level, causing the emission of electromagnetic waves.
Changes to the nuclei and electromagnetic waves.
As a result of radioactive decay, changes in the nucleus can cause the emission of gamma rays, which are a type of electromagnetic wave.
An example of this would be if a nucleus undergoes an alpha or beta decay and the nucleus has been left in an excited state with excess energy. The nucleus can then undergo a gamma decay to reduce this excess energy by emitting is as a gamma ray.
The gamma rays originate from changes in the nucleus of an atom.
An example of a gamma ray emission is shown below.
Practice Question
1. A sample of sodium is placed into a roaring blue bunsen burner flame. A yellow flame colour is then seen. Explain the origin of the yellow flame colour.
2. Many sunscreen products contain UV absorbing chemicals. Suggest how these could work to protect a person from UV rays.
3. Explain why an alpha emitter can also emit gamma rays.
Absorption and Emission of EM Radiation
JJ Thomson and Plum pudding model
Ernest Rutherford and the Nuclear Model
Niels Bohr changing the Nuclear Model
Discovering the Proton and Neutron
Measuring radiation from radioactivity
Radiation types and properties
Random nature of radioactive decay
Radioactive contamination or irradiation
Hazards of contamination and irradiation
Studies on the effects of radiation on humans
Different half lives of radioactive isotopes
Nuclear Fission Chain Reaction
Writing nuclear fission equations
Drawing ray diagrams for a concave lens
Drawing Ray Diagram to produce a virtual image for a convex lens
Drawing ray diagram to produce a real image for a convex lens.
Specular and Diffuse Reflection
Seeing Coloured Objects Part 2
Viewing objects through coloured filters
Transparent, Translucent and Opaque
Accordion Content
Accordion Content