GEN CHEM Flashcards
T or F. Speed of light on vacuum applies on all members of electromagnetic spectrum.
T (all have same speed; diff wavelength and frequency)
A particular wavelength of a visible light corresponds to
color
Which color in the rainbow is refracted the most?
violet (short wavelengths experience more bent/refractions)
white light when shone in a prism will produce separated colors. What do you call the separation
dispersion (they disperse because they are refracted differently)
Who performed the double slit experiment in 1801 and what did it prove
Thomas Young - light behaves as a wave
theoretical objects that absorbs all and emits all
blackbody
Idea that Planck introduced
quantization of energy (energy is not continuous but quantized) - there is a limit to the energy of the light produced as opposed to the classical physics’ idea - thus limited emission and absorption of a blackbody
In photoelectric effect, the electrons ejected at a higher energy results to greater _______
kinetic energy
Electromagnetic radiation (refraction and diffraction) travels in
waves of specific wavelength and frequency
Electromagnetic radiation (blackbody radiation and photoelectric effect) travels in
particles (particle-like way)
According to quantum theory, an atom has only certain quantities of energy, which it can change only by _____ or _______ a ______
absorbing or emitting a photon
By shining white light on a prism, you will get all colors on the spectrum. this is called
continuous spectrum
Shining elements through a prism will not result to same spectrum of white light. what do you call this
line spectrum
How do scientists know the different elements present in a star
Different gases have different (emission) spectrums
Why are spectrums of elements not continuous
elements have different energy levels (energy is thus discrete) - acc to atomic spectra and bohr model
3 postulates of bohr model of single-electron species1
- H atom has only certain allowable energy levels (called stationary states - have specific energy)
- atom does not radiate energy while in one of its stationary states
- atom changes to another stationary state (electron moves to another orbit)
How can bohr model explain nuclear model’s problem with why electrons don’t fall onto the nucleus
atom does not radiate energy while in one of its stationary states (orbit)
Why is there mixing of orbitals sometimes?
The higher the stationary state the close the gap
You will get an emission spectrum if _____ is released
energy
emission spectrum if energy is released and this released energy corresponds to
a different wavelength and therefore different color
who believed that matter could perhaps be wavelike
Louis de Broglie
de Broglie’s wavelength is used to solve wavelength for any matter that has?
speed
An alpha particle is equivalent to
a helium nucleus (he2+)
states that it is impossible to know the exact position and momentum of a particle simultaneously
Heisenberg Uncertainty Principle
principle stating that there are no fixed paths for electrons such as orbits and introduced orbitals
Heisenberg Principle - reason why bohr model can’t be right (it only explained why electrons don’t spiral into nucleus-because if you know the path you can know both position and momentum)
examines wave nature of electrons on atomic scale
quantum mechanics
he derived an equation that is the basis for the quantum-mechanical model of the hydrogen atom
Erwin Schrodinger (1926)
Calculating schrodinger’s equation shows us the allowed values of _______ of an atom
energy
It’s hard to determine the position of an electron due to it being a wave, why?
a wave diffuses
a wave occupies a certain region close to the nucleus called an
orbital
mathematical description of the electron’s matter-wave in terms of position in 3-dimensions
wave function
Solving the ______ using schrodinger eq will give you an idea where the electron could be(probability)
wave function
region in space (3d) where there is a 90 percent of probability of finding an electron
orbital
An atomic orbital is specified by
3 quantum numbers (n, l, ml)
indicates size of an orbital; distance from nucleus; energy level
principal quantum number (n)
related to the shape of an orbital (azimuthal)
angular momentum quantum number (l)
it tells the number of allowed sublevels/subshells
principal qn (n)
prescribes the orientation of the orbital
magnetic quantum number
orbitals that have the same energies
degenerate orbitals
each orbital can occupy a maximum of how many electrons
2
it describes the angular momentum of an electron
spin quantum number (4th quantum number) - ms
If 2 electrons occupy the same orbital they must
have opposite spins (-1/2 and +1/2)
States that no 2 electrons in the same atom can have identical values for all four of their quantum numbers
Pauli’s exclusion principle (no more 2 electrons can occupy and if same orbital must have opposite spins)
In classical theory, it is impossible to predict energy-absorbs infinite; emits infinite- what is this catastrophe
Ultraviolet catastrophe/Rayleigh-Jeans catastrophe - oven & UV
