Topic 2 - Quantum Phenomena Flashcards Preview

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Flashcards in Topic 2 - Quantum Phenomena Deck (17)
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1
Q

De Broglie hypothesis

A

Matter particles have a wave-like nature characterised by the de Broglie wavelength.

2
Q

De Broglie wavelength

A

The wavelength of a matter particle = h/p where p is the momentum of the particle.

3
Q

De excitation

A

Process in which an atom loses energy by photon emission, as a result of an electron inside moving from an outer energy shell to an inner energy shell.

4
Q

Electron volt

A

Amount of energy equal to 1.6x10^-19J defined as the work done when an electron is moved through a pd of 1V.

5
Q

Energy levels

A

The energy of an electron in an electron shell of an atom.

6
Q

Excitation

A

Process in which an atom absorbs energy without becoming ionised as a result of an electron inside an atom moving from an inner energy shell to an outer energy shell.

7
Q

Fluorescence

A

Glow of light from a substance exposed to ultraviolet radiation; the atoms de-excite in stages and emit visible photons in the process.

8
Q

Ground state

A

Lowest energy state of an atom.

9
Q

Ion

A

A charged atom.

10
Q

Ionisation

A

Process of creating ions

11
Q

Photoelectric effect

A

Emission of electrons from a metal surface when the surface is illuminated by light o frequency greater than a minimum value known as the threshold frequency.

12
Q

Photon

A

Packet or ‘quantum’ of electromagnetic waves.

13
Q

Stopping potential

A

The minimum potential that needs to be applied to a metal plate to attract all the photoelectrons emitted from its surface back to the surface.

14
Q

Threshold frequency

A

Minimum frequency of light that can cause photoelectric effect.

15
Q

Types of light spectra.

A

Continuous spectrum - continuous range of colour corresponding to a continuous range of wavelengths, line emission spectrum - characteristic coloured vertical lines, each corresponding to a certain wavelength, line absorption spectrum - dark vertical lines against a continuous range of colours, each line corresponding to a certain wavelength.

16
Q

Wave-particle duality

A

Matter particles have a wave-like nature as well as a particle-like nature; photons have a particle-like nature as well as a wave-like nature.

17
Q

Work function

A

Minimum amount of energy needed by an electron to escape a metal surface.