Chapter 7: Atomic Structure and Periodicity Flashcards
What is electromagnetic radiation
One of the means by which energy travels
through space
fill in the blanks
Electromagnetic Radiation exhibits ________________ behavior, and travels at ________________________ in a vacuum
Exhibits wavelike behavior and travels at the speed of light in a vacuum
What is a wavelengh (λ)
Distance between two
consecutive peaks or troughs in a wave
What is frequency (v)
Number of waves (cycles) per
second that pass a given point in space
What is the unit for the speed of light (c)
2.9979 × 10^8 m/s
What is the realtionship between wavelength and frequency
an inverse relationship
Short-wavelength radiation has a _____________
frequency when compared to long-wavelength radiation
higher
What did Max Planck say
Postulated that energy can be gained or lost only in whole number multiples of h ν
Formula for representing change in energy
ΔE = nhv
n - Integer
h - Planck’s constant
ν - Frequency of electromagnetic radiation absorbed oremitted
What was the conclusion from Planck’s Postulate
Energy is quantized and can occur in discrete units of hν
Formula to calculate quantum energy
ΔE = hv
What did Albery Einstein propose
Proposed that electromagnetic radiation is a stream of particles called photons
What is the photoelectric effect
Phenomenon in which electrons are emitted from the surface of a metal when light strikes it
Regarding the photoelectric effect:
what happends when frequency of light is varied
When frequency of light is varied, no electrons are emitted by a given metal below the threshold
frequency (ν0)
Regarding the photoelectric effect:
When ν < v0:
When ν < v0 , no electrons are emitted, regardless of the intensity of the light
Regarding the photoelectric effect:
When v > v0:
- The number of electrons emitted increases with the intensity of the light
- The kinetic energy (KE) of the emitted electrons increases linearly with the frequency of the light
What is the symbol representing the minimum energy required to remove an electron
E0 = hv0
Formula by Einstein regarding energy and mass
E = mc^2
What is the dual nature of light
Electromagnetic radiation exhibits wave and particulate properties
What did Louis de Broglie claim
He postulated the wave nature of electrons and suggested that all matter has wave properties.