chem #4

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s sublevel

0

The _____ of a wave is the number of wave cycles per second. This quantity is given the symbol ν and has units of s-1 or _____.

Frequency Hz

Which of the following determines the color of visible light? Select all that apply.

Frequency Wavelength

Which of the following statements correctly describes how energy is absorbed by an atom?

The energy of the absorbed radiation must match the difference between the two energy states of the atom.

In a photoelectric diode, no current will flow unless light of a certain minimum threshold frequency is used. Which of the following explains this observation correctly?

The energy of the light photons must match or exceed the energy needed for electrons to break free from the metal.

The distance a wave travels during one cycle is called its _______ . This is usually measured as the distance between two ____________- or two troughs

Wavelength Crests

Visible light is one type of ________________ radiation, which consists of energy propagated by electric and _________________ fields that alternately increase and decrease in intensity as they move through space.

electromagnetic magnetic

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

Atoms, like all other matter, have specific energy levels within them. For an atom to absorb radiation, the energy ___________ of the radiation must match the energy between the two energy levels in the atoms.

gap

Wavelength and frequency are _____ proportional to each other. As wavelength increases, frequency will _____.

inversely; decrease

All waves in the electromagnetic spectrum travel at the same _____ through a vacuum, but differ in their frequency and wavelength. A wave with a long (large) wavelength will have a _____ frequency.

speed low

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

electromagnetic radiation (shortest to longest)

x-ray uv visible light ir radiation radiowave

Which of the following statements correctly describe a photon? Select all that apply.

~A photon is a particle of electromagnetic radiation. ~Matter cannot absorb or emit a fraction of a photon.

Which of the following statements correctly describe the electromagnetic spectrum? Select all that apply.

~All waves in the spectrum travel at the same speed in a vacuum. ~The color of visible light is related to its frequency.

Which of the following statements correctly describe the limitations of the Rutherford model of the atom? Select all that apply.

~This model could not explain why electrons did not emit energy continuously. ~This model could not explain observed atomic line spectra

Which of the following statements correctly describe the magnetic quantum number, ml? Select all that apply.

-The allowed values for ml range from -l to +l. -This value indicates the orientation of an orbital in the space around the nucleus.

Which of the following statements correctly describe the information provided by quantum numbers? Select all that apply.

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

Which of the following statements correctly describe the angular momentum quantum number, l? Select all that apply.

-The value of l dictates the allowed values of ml . _The number of possible l values equals the value of n. _The allowed values of l are determined by the value of n.

d sublevel

2

Which of the following correctly defines an atomic orbital in terms of the quantum-mechanical model of the atom?

A mathematical function that describes the position of the electron-wave in three dimensions

Which of the following statements correctly describe photons? Select all that apply.

A photon can transfer momentum to another particle in a collision. Photons are particles of electromagnetic radiation. Each photon has a specific energy, frequency, and wavelength.

Which of the following correctly expresses energy in terms of Planck's constant? Select all that apply.

E = hc/λ E = hν

Which of the following equations correctly reflects the relationship between energy and frequency?

E= hv

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

Electrons have wavelike motion and are restricted to certain energy states associated with specific wavelengths.

Which of the following statements correctly describe the principal quantum number, n? Select all that apply.

The lower the value of n, the greater the probability that the electron is closer to the nucleus. n can have any positive whole-number value.

Which of the following defines the ground state of an atom?

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

Select the correct statements of the limitations of the Bohr model. Select all that apply.

The model does not account for electron-electron repulsion. The model incorrectly describes electrons as circling the nucleus in fixed, defined orbits.

Visible light and radio waves are both examples of ___________ radiation, which has a dual nature, possessing the properties of both _______________ and waves.

electromagnetic matter

If a solid object is heated to a high enough temperature, it will begin to glow. The color of light it emits depends on the temperature. This relationship between color and temperature implies a relationship between _____.

energy and wavelength

Blackbody radiation studies showed that the _____________ of the highest-energy radiation emitted depends on the temperature of the object.

frequency

The magnetic quantum number has the symbol ml, and this value indicates the _____ of an orbital in space. The ml value is dictated by the value of _____.

orientation l

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.

partiles 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

The speed of light is the ______ of its frequency and wavelength. In a vacuum, this value is a constant, ______.

product; 3.00 × 108 m/s

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

The angular momentum quantum number, l, indicates the ___________ of the orbitals in an atom. A value of l = 0 indicates a(n) ____________ type orbital while a d orbital is indicated by an l value of _____________.

shape s 2

True or false: The Bohr electron energy model is limited to one-electron atoms.

true

Which of the following correctly depict the symbol and units for frequency? Select all that apply.

v Hz

The frequencies and wavelengths of visible light are perceived as different colors. The visible region of the electromagnetic spectrum ranges from higher frequency/shorter wavelength ______ to lower frequency/longer wavelength ______.

violet red

Which statement correctly describes the quantum number n with reference to the Bohr model of the hydrogen atom? Select all that apply.

-an electron with n=2 is at a higher energy than an electron with n=1 -n indicates the energy level of an electron in the atom. -n can have any positive, whole-number value.

When describing orbitals, a node ________. Select all that apply.

-occurs when ψ2 is equal to zero -is a region of zero electron density

Electromagnetic radiation consists of particles called , which exhibit both and particle behavior. The greater the momentum of a photon, the its wavelength.

-photons -wavelike -shorter

Which of the following statements correctly describe the de Broglie wavelength for a particle? Select all that apply.

-wave behavior is most obvious for small, fast-moving particles.-the smaller the object, the closer the wavelength is to the size of the object.-the larger the mass of the particle the smaller its wavelength.

p sublevel

1

1. The principal quantum number n indicates the . 2.The angular momentum quantum number l indicates the 3. The magnetic quantum number ml indicates the 4. The relative size of the orbital is related to the value of 5.The shape of the orbital is related to the value of

1. principal energy level 2. sublevel of the orbit 3. orientation of an orbital in spae 4. the quantum number n 5. the quantum number l

f sublevel

3

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

Angular 0 shape

Which of the following is a consequence of the Heisenberg uncertainty principle?

It is not possible to assign fixed paths for electrons.

Which of the following options correctly describes the limitations of the Bohr model of the atom?

The Bohr model cannot account for the behavior of multielectron species.

Energy is quantized. What does this mean?

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

In order for a current to flow in a photoelectric cell, a photon of light 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.

absorbed energy energy

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 and of _______________- . This model allows a better understanding of the behavior of tiny particles such as electrons.

energy waves

True or false: The atomic orbital of the quantum-mechanical model is very similar to the orbit described by the Bohr model.

false

The speed of a wave is determined by multiplying the _________ of the wave by its wavelength. In a vacuum all electromagnetic radiation travels at a constant speed, the speed of _________________ , which is equal to 3.00 x 108 m/s. (Include a word in the last fill in the blank space, not a number.)

frequency light

An atom is in its lowest energy state, or _____ state, when its electrons are in the lowest possible energy levels. If an electron in the atom absorbs a photon of radiation that is equal in energy to the difference between two energy states, it will move to a higher energy state and the atom is said to be in the _____ state.

ground excited

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 _____ the energy of the system.

levels orbit higher

Arrange the following regions of the electromagnetic spectrum in order of increasing frequency: infrared, microwave, gamma, visible.

microwave < infrared < visible < gamma

The energy levels of the hydrogen atom depend on the value of which quantum number(s)?

n

The principal quantum number is given the symbol ________and has positive, whole-number values starting from _________

n 1

Select the correct symbol and units for wavelength. Select all that apply.

nm λ

A region of zero electron density in an orbital is called a(n) ______.

node

The phenomenon where an electric current is produced by shining a light on a metal plate is called the ___________ effect. The minimum frequency required to cause a current to flow is called the ______________ frequency. This frequency depends on the identity of the metal used.

photoelectric threshold

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) and frequency __________ (expressed in s-1).

photons wavelength

Rutherford's nuclear model of the atom cannot exist according to classical physics because charged particles like electrons in orbit around a nucleus would continuously lose energy. The result would be that as electrons lose energy they would ______.

spiral into the nucleus to collapse the atom

True or false: The sublevels of each principal energy level of the hydrogen atom have the same energy.

true

Which of the following statements correctly describe the photoelectric effect? Select all that apply.

~Current begins to flow immediately when light of the correct frequency shines on the metal plate. ~The threshold frequency differs for different metals used in the photoelectric cell.

Which of the following statements correctly describe wave-particle duality? Select all that apply.

~Energy and mass can be interconverted. ~Matter and energy are different forms of the same entity. ~All matter exhibits wavelike motion.

Which of the following wave properties are related to the amplitude of an electromagnetic wave? Select all that apply.

~Intensity ~Brightness (for visible light)

Which of the following statements correctly describe the Bohr model of the hydrogen atom? Select all that apply.

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

Which of the following correctly define, depict the symbol, and provide the units for the speed of electromagnetic radiation (light)? Select all that apply.

~c = λ × υ ~c = 3.00 × 108 m/s ~Light moves at a constant distance per time.


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