Ch 6: Quantum Theory and the Electronic Structure of Atoms Flashcards
Traditional cancer treatment therapies involve the use of powerful ionizing radiation, such as X rays or _____ rays. Ionizing radiation damages the ___ of cancer cells, preventing their continued replication – although it does the same to healthy, noncancerous cells.
gamma
DNA
Photodynamic therapy works by irradiation with visible light, which is far less _________ than X-ray or gamma radiation, and thus safer to use. Treatment begins with the administration of a photosensitizer (a substance that undergoes reaction when irradiated) that is ___________ taken up by cancerous tissue. Subsequent irradiation with a specific wavelength of visible light causes the photosensitizer to produce an especially reactive form of oxygen known as _______ oxygen, which damages the cancerous cells and prevents further replication.
energetic
selectively
singlet
p. 233
When we say “light”, we generally mean visible light, which is the light we can detect with our eyes. Visible light, however, is only a small part of the continuum of radiation that makes up the __________ spectrum.
electromagnetic
p. 214
Wavelength (λ) is defined as…
….the distance between identical points on successive waves.
frequency (“nu”, ν) is defined as…
…the number of waves that pass through a particular point in 1 second.
amplitude is defined as…
…the vertical distance from the midline of a wave to the top of the peak or the bottom of the trough
In 1873, who proposed that visible light is composed of electromagnetic waves?
James Clerk Maxwell
What is Planck’s constant?
The value is 6.63 x 10-34 J·s
In 1900, Max Planck …
What is the relationship between energy and wavelength?
energy and wavelength are INVERSELY proportional, because of these equations:
E = hν
c = λν
When using Planck’s constant to calculate the de Broglie wavelength of a “particle”, what units should this constant have (in order to cancel with other units and get a wavelength in m?)
kg•m2/s
The principal quantum number (n) designates….
The principal quantum number can have integral values of 1, 2, 3, and so forth, and it corresponds to the quantum number in Bohr’s model of the hydrogen atom.
…the size of the orbital.
The angular momentum quantum number (ℓ) describes…
…the shape of the atomic orbital
The magnetic quantum number m<u>l</u> describes…
…the orientation of the orbital in space
To specify the electron’s spin, we use the electron spin quantum number ( m<u>s</u> ) . Because there are two possible directions of spin, opposite each other, ms has two possible values:
___ and ___. Two electrons in the same orbital with opposite spins are referred to as “______.”
+½ and -½
paired
The values of ℓ are integers that depend on the value of the principal quantum number, n. For a given value of n, the possible values of ℓ range from _ to ___. If n=1, there is only one possible value of ℓ**; that is, 0 (n−1 where n=1).
If n=2, there are two values of ℓ: 0 and 1. If n=3, there are three values of ℓ: 0, 1, and 2.
0 to n-1
The value of ℓ is designated by the letters s, p, d, and f, where s corresponds to a value of ℓ equal to….
- ℓ=0*
- ℓ=1*
- ℓ=2*
- ℓ=3*
What is the electron configuration for Neon?
1s22s22p6
What is the electron configuration for Argon?
1s22s22p63s23p6
What does the Aufbau principle state?
An e- always goes into the next available orbital with the lowest energy.
What does the Pauli exclusion principle state?
No more than 2 e-‘s can occupy each atomic orbital. The electrons must be of opposite spin.
What does Hund’s principle state?
When there are two or more atomic orbitals with the same energy, an e- will occupy this before it will pair up with another electron.
Is the ENERGY of particular type of radiation directly proportional to the wavelength of the wave or the frequency?
Energy = hν
Therefore, energy is directly proportional to FREQUENCY.
Order the following types of electromagnetic radiation according to INCREASING frequency/energy.
visible light
microwave
radio waves
ultraviolet
gamma rays
infrared
x-rays
radio waves < microwaves < infrared < visible light < ultraviolet light < X rays < gamma rays
What mnemonic can you use to help you remember the range of electromagnetic radiation in order of decreasing frequency (increasing wavelength)?
Get Xtra Umbrellas. Vera Is Making Rain!
Gamma rays (1020 Hz)
X-rays (1018)
Ultraviolet light (1015-16 Hz; so named bc it has a higher frequency than visible light)
Visible light (1014 Hz; 400-700 nm)
Infrared (1013 Hz; so named bc it has a lower frequency than visible light)
Microwaves (~1010 Hz)
Radio waves (~106 Hz)
In regard to stationary waves, some points on a guitar string, for example, are called _____, and do not move at all. There is a node at each end, and there may be one or more nodes between the ends. The greater the frequency of vibration, the shorter the __________ of the standing wave and the greater the number of nodes. According to de Broglie, an electron in an atom behaves like a standing wave.
nodes
wavelength
p. 250
De Broglie argued that if an electron does behave like a standing wave in the hydrogen atom, the wavelength must fit the circumference of the orbit exactly; that is, the circumference of the orbit must be an ________ _______ of the wavelength. Otherwise, the wave would partially cancel itself by destructive interference on each successive orbit, quickly reducing its amplitude to zero. What equation gives the relationship between the circumference of an allowed orbit (2∏r), and the wavelength (λ) of the electron?
integral multiple
2∏r = nλ
(r is the radius of the orbit, λ is the wavelength of the electron wave, and n is a positive integer (1, 2, 3, …). Because n is an integer, r can have only certain values (integral multiples of λ) as n increases from 1 to 2 to 3 and so on. And, because the energy of the electron depends on the size of the orbit (or the value of r), the energy can have only certain values too. Thus, the energy of the electron in a hydrogen atom, if it behaves like a standing wave, must be quantized.)
What formula do we need to know in order to calculate the de Broglie wavelength or mass of a particle?
λ = h / mu
(u in this formula is velocity in m/s; also, mass must be in kg for units to cancel correctly.)
The “m∗u” part of the previous equation can also give us the _______ of a particle. This quantity (or vector rather) has units of kg∗m/s, or N∗s.
(Remember that a N is a derived SI unit: 1 N = 1 kg∗m/s2)
momentum
What calculating the ΔE of an atom undergoing transition between levels, if ΔE is +, a photon will be ________. If ΔE is -, a photon will be _______.
absorbed
emitted
As electrons go from a lower energy level to a higher energy level, they get AHED, which stands for…..
Absorb light (or energy)
Higher potential
Excited
Distant (from the nucleus)
[mnemonic from Kaplan Gen Chem Review, p. 13]
A collection of orbitals with the same value of n is frequently called a ____. One or more orbitals with the same n and ℓ values are referred to as a _______.
shell
subshell