Chapter 4 Quiz Flashcards
How is light as a wave?
A type of electromagnetic radiation, along with X-rays, ultraviolet and infrared light, microwaves, and radio waves.
Waves have a _______ ______ and can be measured by ________ & _________.
repetitive nature; wavelength; frequency
What are the units of wavelength?
cm or nm
What are the units for frequency?
Waves/sec or hertz (Hz)
How are frequency and wavelength related to each other?
c=wavelength x frequency
What is c
c=speed of light or 3.00 x 10^8 m/s
How is light as a particle?
By the photoelectric effect, when the emissions of electrons from metal when light shines on it
Light has to have a minimum frequency for this to occur
What is Planck’s theory and constant?
- Objects do not emit electromagnetic energy constantly
- Instead energy is emitted in small specific packets called quanta
What is a quantum of energy?
The minimum amount of energy that can be lost or gained by an atom
E=hv
Equation showing relationship between quantum of energy and frequency
Who expanded on Planck’s theory and how?
Einstein expanded on Planck’s theory by introducing that light has a dual wave-particle nature.
Light can be thought of as …
a stream of particles
What is a photon?
A particle of electromagnetic radiation w/no mass and carrying a quantum of energy
What is ground state?
Lowest energy state of an atom
What is excited state
An atom has a higher potential energy than in its ground state
What happens when an electron returns to ground state?
It gives off energy in form of electromagnetic radiation
What did specific frequencies of light and not a continuous spectrum show scientists?
Electrons exist in specific energy states
What did the Bohr Model propose?
A hydrogen-atom model that linked the atom’s electron to photon emission
According to the Bohr model…
the electron can circle the nucleus only in allowed paths or orbits
Electron and atoms are in the lowest energy state when the electron is…
in the orbit closest to the nucleus
Energy of the electron is higher when the electron is in orbit…
successively farther from the nucleus
What were the issues with Bohr’s Model?
- The model does not explain atoms with more than one electron
- Does not explain the chemical behavior of atoms
Behavior of electrons is similar to…
the behavior of waves
When can electron waves exist?
Only at certain frequencies, which correspond to specific energies
How are electrons detected?
By their interaction with photons, but the photons knock the electron off its course
What is the Heisenberg Principle?
It is impossible to determine simultaneously both the position and velocity (speed) of an electron
What did the Schrodinger Wave Equation develop?
an equation that treated electrons in atoms as waves and quantization of electron energies was an outcome of the equation.
What is the quantum theory?
mathematically describes the wave properties of electrons and other very small particles.
What are orbitals?
3D region around the nucleus that indicates the probable location of an electron.
What are the conclusions and beginnings of the Quantum Atomic Theory?
- Wave functions allow us to determine the probability of finding an electron at a given place around the nucleus
- Electrons don’t travel in neat orbits like Bohr proposed. They exist in certain regions called orbitals
What are quantum numbers?
The properties of atomic orbitals and the properties of electrons in orbitals?
What are the principals of Quantum Number?
- Symbolized by n
- Indicates the main energy level occupied by the electron
- As n increases the electron’s energy and its distance from the nucleus increases
Can more than one electron have the same n value? Are they in the same shell?
Yes; yes
The total number of orbitals in each shell or energy level is…
n^2
What are electron configurations?
The arrangement of electrons in an atom
Does each element have a unique electron configuration?
Yes
What is ground -state electron configuration?
The lowest energy arrangement of the electrons for an element
What is Aufbau Principle?
Electrons fill the lowest energy orbitals first
What is Orbital Order?
1s,2s,2p,3s,3p,4s,3d,,4p,5s,4d,5p,6s,4f,5d,6p,7s,7p
S orbital has a max subscript of…
2
P orbital has a max subscript of…
6
D orbital has a max subscript of…
10
F orbital has a max subscript of…
14
What is the Pauli Exclusion Principle?
Each orbital can hold TWO electrons with opposite spins.
What is Hund’s Rule?
Within a sublevel, place one electron per orbital before pairing them.
What is Noble Gas Configuration?
A shorthand method of writing the electron configuration?
What is Planck’s constant?
6.626 x 10^-31
