Chem Ch 7

An orbital that has a value of ______ for the angular momentum quantum number ℓ is known as a p orbital. A p orbital has a ______ shape.

1 dumbbell

Bohr Model of the Hydrogen Atom facts

1. Only certain energy levels are allowed within the hydrogen atom. 2. The atom is in its lowest energy state when the electron is in the orbit closest to the nucleus. 3. Each energy state of the hydrogen atom is associated with a fixed circular orbit of the electron around the nucleus.

Match each principal energy level quantum number to the number of electrons that can be accommodated at that level. n1 n2 n3 n4

2 8 18 32

Speed of light (c) in vacuum

3.00 x 10^8 m/s

Match each electron to the set of quantum numbers that could describe it. 3,0,0 3,1,0 4,2,2 4,1,-1 3s, 4d, 4p, 3p

3s 3p 4d 4p

Match

4, 0, 0. 4s orbital 5, 3, -2 5f orbital 2, 1, -1 2p orbital 3, 1, 1 3p orbital

Photons are

A component of the particle of electromagnetic radiation Matter cannot absorb or emit a fraction of a photon The higher the freq, the higher the energy Different amounts of energy

Which of the following statements are true regarding assigning electrons to atomic orbitals? Select all that apply.

A given energy level n will also contain n subshells. For any principal energy level n, the maximum number of electrons it can contain is equal to 2n2.

What occurs when the electron in a hydrogen atom moves from a higher-energy state to a lower-energy state?

A photon is emitted whose energy is equivalent to the difference between the two energy states.

hydrogen atom moves from the n = 5 to n = 3 energy level?

A photon of 1.55 x 10-19 J is emitted by the atom.

Which statement correctly describes what occurs when the electron of the hydrogen atom moves from the n = 2 to n = 4 energy level?

A photon of 4.09 x 10-19 J is absorbed by the atom.

Electron moves from a higher n to a lower n matches

A photon of radiation is emitted by the atom.

how to place electrons in orbitals of the same sublevel?

All unpaired electrons in a sublevel should have parallel spins. One electron must be placed in each orbital of equal (degenerate) energy before electrons are paired up.

m s Magnetic spin

Always = North, clockwise, up, +1/2 South, counter clockwise, down, - 1/2

Which of the following statements correctly reflects the most important consequence of Pauli's exclusion principle?

An atomic orbital can hold a maximum of two electrons as long as they have opposite spins. no two electrons in the same atom can have the same four quantum numbers

Aufbau Principle

As protons are added to the nucleus across the periodic table, electrons are also added to orbitals.

Electron moves from a lower n to a higher n

Choice, A photon of radiation is absorbed by the atom. A photon of radiation is absorbed by the atom.

Solid heated to a high temperature

Choice, Spectrum of continuous wavelengths Spectrum of continuous wavelengths

Which of the following elements exhibit an irregular filling pattern of the orbitals? Select all that apply.

Cu Cr

principal quantum number n

Distance of e- from the nucleus n = 1,2,3,4,... The higher the number, the higher the energy level

Equation of Quantization of energy

E = hv E = energy of a quantum of radiation h = plancks constant v = frequency of radiation

Relationship between energy and Frequency

E=hv Direct Proportional

What is occurring when a hydrogen atom emits a photon in the ultraviolet region with a wavelength of 103 nm?

Electron transition from n = 3 to n = 1

Which of the following are consequences of electron shielding in a many-electron atom?

Electrons at the 3s level experience a smaller nuclear charge than electrons at the 1s level. Electrons at the 2p level experience a greater nuclear charge than electrons at the 3p level.

The spectra of radiation produced by substances such as hot metals, or gases in an electric current, are known as

Emission spectra

wavelength (lambda upside down y)

Horizontal distance between the crests or between the troughs of two adjacent waves measured in nm OR m

consequence of the Heisenberg uncertainty principle?

It is not possible to assign an electron to a fixed orbit.

Gaseous substance in an electrical discharge

Line spectrum of discrete wavelengths

light waves

Maxwell - Visual light is electromagnetic waves

Which of the following statements correctly describe how an orbital diagram is constructed? Select all that apply.

Orbitals may be listed horizontally or vertically. Electrons are placed by filling lower energy levels first.

De Broglie

Scientist who suggested that all moving particles had a wave motion associated with them

Hydrogen atom emission series

Series n. Specrtum Region Lyman 1. Ultraviolet Balmer. 2. visible and ultraviolet Paschen. 3. infrared Brackett. 4. infrared

ground state of an atom?

State of lowest energy, in which all electrons are in the lowest possible orbitals

Bohr equation, En = -RH (1/n2)

The allowed energies of the electron in a hydrogen atom

angular momentum quantum number (l)

The geometry of the orbit symbolized by l, indicates the shape of the orbital l = n-1 l = 0. s. sphere l = 1. p. dumbbell or 2 lobe structure l = 2 d. l = 3. f

Why does each element have its own unique atomic line spectrum?

The lines in the spectrum correspond to the differences between the specific energy states in the atom.

quantum mechanics?

The movement of each electron in the atom cannot be described by classical physics. Electrons exhibit behavior of both waves and particles. Each electron occupies a three-dimensional space near the nucleus. This space is described by a wave function.

limitations of the atomic model that preceded Bohr's hydrogen atom model?

The old model could not explain why electrons did not emit energy continuously. The old model could not explain observed atomic line spectra. The old model could not explain why electrons did not spiral into the nucleus of the atom.

quantum number facts

The quantum number ℓ indicates the shape of an orbital. The quantum number n indicates the principal energy level of an orbital. The relative size of the orbital is indicated by the value of n.

Which of the following statements correctly describe the spin quantum number of the electron? Select all that apply.

The spin quantum number has values of +1212 or -1212. The spin quantum number is a property of the electron itself.

Energy is quantized. What does this mean?

There is a basic unit of energy that cannot be subdivided further.

True or false: Emission spectra of atoms in the gas phase do not show a continuous spread of wavelengths.

True ---, light is only emitted at specific wavelengths---

Line emission spectrum of hydrogen

Uses a prism to Provide evidence for the existence of electrons in discrete energy levels, which converge at higher energies.

Schrodinger wave equation (w psi)

a description of how the electron matter wave varies with location and time around the nucleus of a only a hydrogen atom energy of e- with a given wave function (w) Probability of finding e- in a volume of space

Probability density

a value that represents the probability that an electron will be found at a given point in space Where 90% of the e- density is found

The _____________ momentum quantum number ℓ can have any integer value from __________ to n - 1 for a given value of n.

angular 0

ml (magnetic quantum number)

describes the orientation in space each sub-shell has: all values from -l to positive l including 0, think of number of possible electrons for each energy level and then orbital notation to determine how many #s are needed. l = 0 then S orbital = 0 l = 1 then P orbital = -1, 0, 1 l = 2 then D orbital = -2, -1, 0, 1, 2 l = 3 then F orbital = -3, -2, -1, 0, 1, 2, 3

A gaseous element that is subjected to an electrical discharge will emit

electromagnetic radiation only at specific wavelengths

A given photon of electromagnetic radiation has a characteristic frequency, and thus contains a fixed amount of

energy

Each element has its own atomic line spectrum, consisting of fine lines of individual wavelengths that are characteristic for the element. This occurs because the atom contains specific _____________ levels, and an atom can only absorb or emit radiation that corresponds to the energy ______________, between these levels

energy difference

In Bohr's model of the atom, the quantum number n is associated with the _____ of an electron orbit. The lower the n value, the _____ the electron is to/from the nucleus and the _____ the energy level.

energy closer lower

In an atom, an electron occupying the most stable energy state available is said to be in the _____________ state. An electron that is not occupying the most stable energy state available is said to be in a(n) ____________ state.

ground excited

In the Bohr hydrogen atom, a higher value for the quantum number n indicates that the electron is at a ______ energy level, and is ______ the nucleus.

higher; farther from

As the value of the principal quantum number n increases, the number of possible values of ℓ and mℓ ______, and the number of allowed orbitals ______.

increase; increases

According to the Bohr model for the hydrogen atom, the energy of the atom is not continuous but has certain discrete energy ____________ each of which is related to a fixed circular______________ of the electron around the nucleus. The farther the electron is from the nucleus, the ____________

levels orbit higher

(w psi) is a function of 4 Quantum Numbers

n, l, ml, ms

Pauli Exclusion Principle

no two electrons in the same atom can have the same set of four quantum numbers states that a maximum of two electrons can occupy a single atomic orbital but only if the electrons have opposite spins

A diamagnetic atom contains ______ unpaired spin(s) and is ______.

no; slightly repelled by a magnet

An orbital diagram consists of a series of boxes, each of which represents one atomic _______________. Electrons are represented in the boxes by ____________, and the direction of each of these is associated with the ___________ of the electron.

orbital arrows spin

describe p orbitals?

p orbitals always occur in groups of three. The p orbitals of a group are perpendicular to each other. A p orbital has a dumbbell shape with two lobes, one on either side of the nucleus.

Hund's rule states that when orbitals of equal energy are being populated with electrons, the most stable configuration is the one with the greatest number of ______. Multiple choice question.

parallel spins

Atoms can display magnetic properties, based on the magnetic spins of their electrons. An atom that contains one or more unpaired electrons is said to be ______, while an atom that contains no unpaired electrons is said to be ______.

paramagnetic; diamagnetic

Electrons, like all other matter, exhibit the dual behavior of both _____________ and waves. Since electrons travel like waves their energy is restricted to certain energy , __________ each of which is associated with a specific wavelength.

particles levels

Heisenberg's uncertainty principle states that it is not possible to know the exact momentum and ___________ of a particle simultaneously. In terms of atomic structure, this means that we cannot determine fixed ________________ for electrons but can only determine the _________________ of finding an electron in a given region of space.

position orbits probability

Heisenberg postulated that it is impossible to know both the __ and __ of a particle with complete certainty. This means that it is impossible to define the __ of an electron in an atom.

position; momentum; path

A condensed electron configuration includes a noble gas core. The notation begins with the symbol of the noble gas that is_______to the element being depicted. The noble gas symbol is enclosed in _______

prior brackets

Energy is not continuous, but is quantized or divided into "packets" each of which contains a definite amount of energy. An energy "packet" is called a(n) _____ and the energy of each "packet" is directly proportional to its _____.

quantum; frequency

Rank the sublevels for a particular principal energy level in order of increasing energy for a multielectron atom (lowest at the top, highest at the bottom).

s p 'd' f

An orbital with ℓ = 0 is called a(n) _____ type orbital and has a(n) _____ shape. There is always a total of _____ orbital(s) of this type for each principal energy level.

s; spherical; 1

Quantum number facts

shell - electron with the same value of n Subshell - electrons with the same values of n and l Orbitals - electrons with the same value of n, l, ml electron - 2 electrons in each orbital

A 2s or 2p electron in a carbon atom does not experience as strong an electrostatic attraction for the nucleus as a 1s electron does. These electrons at the n = 2 level are said to be _______ by electrons at the n 1 level

shielded

Bohr's model of the hydrogen atom

structural model in which an electron moves around the nucleus only in circular orbits, each with a specific allowed radius; the orbiting electron does not normally emit electromagnetic radiation, but does so when changing from one orbit to another. e- can only have specific quantized energy values Light is emitted as e- moves from one energy level to a lower level n (principal quantum numbers) = 1,2,3

electromagnetic spectrum

the complete range of electromagnetic waves placed in order of increasing frequency 400nm - 700nm is what we can see

Amplitude

the height of a wave's crest

the quantum number n

the lower the value the closer to the nucleus any whole number positive value

Frequency (nu) v

the number of complete wavelengths that pass a point in a given time (Hz = 1 cycle/sec)

True or false: An electron whose angular momentum quantum number is 2 can have a value of -2 for the magnetic quantum number mℓ.

true

Planck postulated that energy

was quantized rather than continuous

De Broglie reasoned that an electron in a hydrogen atom can only occupy certain energy levels because it is behaving like a standing

wave

In the quantum mechanical model of the atom, an electron is viewed as a wave-particle that occupies a three-dimensional space near the nucleus. The movement of the electron is described by a ________ function, which is also called an atomic ___________

wave orbital

All matter behaves as though it moves in a(n) _____________ . The motion of any particle can be described by the de Broglie equation, which relates the wavelength of a particle to its __________________ and speed.

wave mass

Waves can be characterized by their ______________, which can be measured in units such as meters or nanometers; and their ________, which can be measured in hertz.

wavelength / Frequency

The speed (u mu) of the wave =

wavelength x frequency Inverse relationship

Emission spectra of some elements

way of identifying element by color on the spectrum