Chemistry: Ch. 7

S sublevel

0

P sublevel

1

D sublevel

2

F sublevel

3

- shielded

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.

- energy - waves

A central concept in quantum mechanics is that both matter and ______ are alternate forms of the same entity and therefore both exhibit dual characteristics of particles & of ______. This model allows a better understanding of the behavior of tiny particles such as electrons.

No unpaired electrons

A diamagnetic species has . . .

One or more unpaired electrons

A paramagnetic species has . . .

Paramagnetic

A species that is attracted to a magnetic field is. . .

Diamagnetic

A species that is slightly repelled by a magnetic field is . . .

- levels - orbit - higher

According to Bohn 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 __-____ the energy of the electron

- wave - mass

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

- probability - wave

An atomic orbital defines the ________ of finding an electron in a particular region of an atom. This electron density is defined by the square of the Schroedinger _______ function.

3, 1, 0

An electron in a 3p orbital

3, 0, 0

An electron in a 3s orbital

4, 2, 2

An electron in a 4d orbital

4, 1, -1

An electron in a 4p orbital

Paramagnetic Diamagnetic

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

[Ar] 4s^2 3d^2

Correct condensed electron configuration for titanium

- matter cannot absorb or emit a fraction of a photon - a photon is a particle of electromagnetic radiation

Describe a photon

- an atomic orbital is the square of a Schroedinger wave function - an atomic orbital defines the probability of finding an electron in a given region of an atom

Describe an atomic orbital.

- atoms in the gas phase only emit radiation at specific wavelengths

Describe an emission spectrum of an element in the gas phase.

- each electron occupies a 3-D space near the nucleus. This space is described by a wave function - movement of each electron in the atom cannot be described by classical physics - electrons exhibit behavior of both waves & particles

Describe atom in terms of quantum mechanics

- 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

Describe how to place electrons in orbitals of the same sublevel.

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

Describe information provided by quantum numbers

- p orbitals of a group are perpendicular to each other - p orbital has a dumbbell shape with 2 lobes, one on either side of the nucleus - p orbitals always occur in groups of 3

Describe p orbitals:

- only certain energy levels are allowed within the hydrogen atom - the atom is in its lowest energy state when the electron is in the orbit closest to the nucleus - each energy state of the hydrogen atom is associated with a fixed circular orbit of the electron around the nucleus

Describe the Bohr model of the hydrogen atom.

- the larger the mass of particle the smaller its wavelength - a fast-moving particle will have a short wavelength - wave behavior is most obvious for small, fast-moving particles

Describe the de Brogile wavelength for a particle

- all waves in the spectrum travel at the same speed in a vacuum - the color of visible light is related to its frequency

Describe the electromagnetic spectrum.

- this value indicates the orientation of an orbital in the space around the nucleus - the allowed values for m sub script l range from -l to +l

Describe the magnetic quantum number, symbol m subscript l?

- n is an integer, & can have values 1, 2, 3, . . . - n indicates the energy level of an electron in the atom

Describe the quantum number n, with with reference to the Bohr model of the hydrogen atom

A photon of 4.09 X 10^-19 J is absorbed by the atom

Describe what occurs when the electron of the hydrogen atom moves from the n=2 to n=4 energy level.

- energy - difference

Each element has its own atomic line spectrum, consisting of the lines of individual wavelengths that are characteristic for the element/. This occurs b/c the atom contains specific _________ levels, an an atom can only absorb or emit radiation that corresponds to the energy ________ between these levels

- photons - wavelength

Electromagnetic radiation consists of particles called ______, each of which has a discrete amount, or quantum, of energy. However, since electromagnetic radiation also has wave properties, each particle is also characterized by a specific ________ (usually expressed in nm) & frequency (expressed in s^-1)

- particles - levels

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.

- quantum - frequency

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 _______ & the energy of each "packet" is directly proportional to its _______.

-there is a basic unit of energy that cannot be subdivided further

Energy is quantized. What does this mean?

E = hv E = hc / lambda

Express energy in terms of Planck's constant

The lowest energy state of an atom, where all electrons are in the lowest energy levels possible

Ground state of atom?

-one -paired

Hund's rule states that when a sub level sonatina several orbitals of equal energy, _____ electron must be placed in each orbital before elections are _______.

- energy - closer - lower

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

- absorbed - energy - frequency

In order for electrons to be ejected from the surface of a metal by light, the photon must be _______ by an electron in the metal. For this to occur the _______ of the photon must be equal to or greater than the energy needed to remove the electron from its energy state. It is the _______ of the light that is important, not its intensity.

- the energy of the photons must match or exceed the energy needed for electrons to break free form the metal

In the photoelectric effect, electrons will not be ejected from the surface of a metal unless light of a certain minimum "threshold" frequency is used. Which of the following explains this observation correctly?

- wave - orbital

In the quantum mechanical model of the atom, an electron is viewed as a wave-particle that occupies a 3D space near the nucleus. The movement of the electron is described by a _______ function, which is also called an atomic _______.

- photoelectric - threshold

Phenomenon where electrons are ejected from surface of certain metals exposed to light is called the _______ effect. the minimum frequency required to cause electrons to be ejected is called the _______ frequency.

- 5p - 4d - 5s - 2p - 2s

Place atomic sub shells into order in which they would be filled with electron, beginning with the subs hell that is lowest in energy at the bottom of the list.

3d 4s 3p 3s 2p

Place following atomic sub shells into order which they would be filled with electrons, beginning with the subs hell that is lowest in energy at the bottom of the list

S < p < d < f

Rank sub levels for particular principal energy level in order of increasing energy for a multi electron atom. (Lowest at top, highest at bottom)

[Ar] 4s^2 3d^6 1s^2 2s^2 2p^3 [Ne] 3s^2 3p^4

Represent proper ground state electron configurations

True

T/F: Emission spectra of atoms in the gas phase do not show a continuous spread of wavelengths.

- exclusion - 2

The Pauli _______ principle guarantees that no 2 electrons in the same atom have the same quantum number description. This means that the maximum number of electrons that can be accommodated by any orbital is ______.

- angular - 0 - shape

The ________ momentum quantum number has the symbol l & can take values from ______ to (n-1). This number is related to the ______ of the orbital.

Sub level of the orbital

The angular momentum quantum number l indicates the . . .

- sub level - s - 2

The angular momentum quantum number l indicates the ______ of an orbital in an atom. A value of l=0 indicates a ____ type orbital while a d orbital is indicated by an l value of ___.

Orientation of an orbital in space

The magnetic quantum number m subscript l indicates the . . .

- n - 1

The principal quantum number is given the symbol _______ & has positive, whole-number values starting from _______.

Principal energy level

The principal quantum number n indicates the

The quantum number n

The relative size of the orbital is related to the value of . . .

The quantum number l.

The shape of the orbital is related to the value of . . .

Emission spectra

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

- product; decrease

The speed of a wave is the _______ of its wavelength & frequency. As wavelength increases frequency will _______.

- they have the same outer electron configuration

What accounts for the observation that Li, Na, K, and Cs have similar chemical properties.

- all unpaired electrons in a sub level should have parallel spins - one electron must be placed in each orbital of equal (degenerate) energy before electrons are paired up

What correctly describes how to place electrons is orbitals of the same sub level?

E = hv

What correctly reflects the relationship between energy & frequency?

- distribution of electrons among an atom's orbitals

What is meant by the electron configuration of an atom?

- lower - first - spin

When drawing an orbital diagram, orbitals of ______ energy are filled first. by convention, the _____ electron in a given orbital is designated as ^ & the direction of the arrow indicates the electron _____.

N

Which element has the ground-state electron configuration is 1s^2, 2s^2, 2p^3?

- orientation in space - energy - space

Which of following properties of an atomic orbital are described by the 3 quantum numbers n, l, and m sub l

- electrons have wavelike motion & are restricted to certain energy states associated with specific wavelengths

Why are electrons restricted to certain, discrete energy levels within an atom?

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

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