Y1 Ch 03 Electrons and Energy Levels Flashcards Preview

Physics A Level AQA > Y1 Ch 03 Electrons and Energy Levels > Flashcards

Flashcards in Y1 Ch 03 Electrons and Energy Levels Deck (16)
Loading flashcards...
1
Q

Electrons gain and lose energy by …

A

Losing/gaining photons.

2
Q

To move up an energy level the electron must absorb …

A

a photon that had the exact same amount of energy as the difference between the two energy levels.

3
Q

Excitation

A

when an electron moves up an energy level.

4
Q

Quickly after excitation the electrons …

A

fall back due to the unstable nature of the electron.

5
Q

Ionisation

A

when an electron gains so much energy that it leaves the atom.

6
Q

A diffration grating is …

A

A piece of transparent material ruled with very closely spaced lines, used to see the diffration of light.

7
Q

Continuous spectrum

A

A spectrum where all frequenies of radiation or colours of light are possible.

8
Q

Line spectrum

A

A spectrum of discrete colours of light.

9
Q

Emission spectra

A

A bright spectrum seen when photons are emittied by atoms.

10
Q

Absorption spectrum

A

A spectrum of dark lines seen on a coloured background produced when a gas absorbs photons.

11
Q

Spectra are formed because

A

When the electrons fall down from their excited state they release a photon with the same amount of energy as the differnce between the two energy levels. This photon will have a certain fequency due to E = hf. So only certain frequenies are shown.

12
Q

Fluoresence

A

When a substance absorbs short wavelegth electromagnetic radiation and emitts longer wavelength radiation.

13
Q

Fluorescent tube

A

A type of light bulb that gives out light when its inner coating fluoresces.

14
Q

Thermionic emission

A

When the free electrons are released from a heated filament.

15
Q

Plasma

A

A mixture of ions and electrons on a gas.

16
Q

How does a fluorescent tube work?

A

The tube is filled with mercury vapour and coated inside with phosphors. The cathode is heated causing thermal emission. This releases free electrons which excite the electrons of the mercury. When they drop down they release UV photons. These photons strike the phosphors and are absorbed and are remitted at visible light.