Chem 115: Chapter 7 Smartbook

Which of the following statements correctly describe an s orbital?

- A 2s orbital has two regions of high electron density. - An s orbital has a spherical shape.

Which of the following statements correctly describe p orbitals?

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

Which of the following statements correctly describe the magnetic quantum number, ml?

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

Select the statements that correctly recall the meaning of the Schrodinger equation.

- The electron has both particle and wave behavior, represented by wave functions, ψ. - The location of an electron must be described statistically instead of absolutely.

Which of the following statements correctly describe the principal quantum number, n?

- 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 statements correctly describe the atom in terms of quantum mechanics?

- The movement of each electron in the atom can be described by a wave function. - 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.

Which of the following statements correctly describe the angular momentum quantum number, l?

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

Which of the following statements correctly describe the information provided by quantum numbers?

- 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. - The quantum number l indicates the shape of an orbital.

Which of the following statements correctly describe atomic d orbitals?

- d orbitals are only possible for n ≥ 3. - d orbitals always occur in groups of five.

Which of the following statements correctly describe the principle quantum number, n?

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

Which of the following statements correctly describe wave-particle duality?

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

Which of the following statements correctly describe photons?

-photons are particles of electromagnetic radiation. - each photon has a specific energy, frequency and wavelength. - a photon can transfer momentum to another particle in a collision

For a principal quantum number n = 3, what values of the angular momentum quantum number l are allowed?

0, 1, 2

Which of the following sets of quantum numbers are allowed?

1, 0, 0 2, 1, -1

A p orbital has ______ regions or lobes of high electron probability on either side of the nucleus. This gives the orbital a dumbbell shape with a(n) ______ or region of zero electron density at the nucleus.

2 node

Which of the following sets of quantum numbers could describe an electron in a 4p orbital?

4, 1, 0 4, 1, -1

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 describes a photon?

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

In order for a current to flow into 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 the intensity.

Absorbed Energy Frequency

Which of the following statements correctly describes the quantum number n with reference to the Bohr model of the hydrogen atom?

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

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 wave properties are related to the amplitude of an electromagnetic wave?

Brightness (for visible light) Intensity

Which of the following correctly expresses energy in terms of Planck's constant?

E= hv E= hc/λ

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

E=hv

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

Electromagnetic; particles

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.

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

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

Energy Waves

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 temperature implies a relationship between _____.

Energy and wavelength

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

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

False An orbit in the Bohr model describes a well-defined circular path for an electron. An atomic orbital is a mathematical function with no direct physical meaning, although this function can be solved to determine regions within the atom where an electron of a particular energy is most likely to be found.

The ________ of a wave is the number of wave cycles per second. This quantity is given the symbol v and has units of s^-1 or _______.

Frequency; Hz

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 10^8 m/s.

Frequency; light

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

An atom is in its lowest 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 stat and the atom is said to be in the _______ state.

Ground; excited

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

Inversely; decrease

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

It is not possible to assign fixed paths for electrons

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

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

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 _______.

Photons Wavelength

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

Heisenberg's uncertainty principle states that it is 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 Probably

Energy is not continuous, but is quanitized 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

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

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 _______.

Sublevel s 2

Which of the following statements correctly describes the Bohr model of the hydrogen atom?

The atom is in its lowest 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. Only certain energy levels are allowed within the hydrogen atom.

Which of the following statements correctly describe the electromagnetic spectrum?

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

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 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 the energy needed for electrons to break free from the metal.

Which of the following correctly defines the amplitude of a wave?

The height of each crest or depth of each trough.

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

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

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.

Which of the following statements correctly describe the photoelectric effect?

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

Energy is quantized. What does this mean?

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

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

The Schroedinger wave equation relates the energy of an atom to its electrons in terms of the _____ function of the electron. Each solution to the equation represents an allowed ______ state of the atom and is associated with a particular atomic orbital.

Wave Energy

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 Oribital

Black body radiation studies showed that the _______ of the highest-energy radiation emitted depends on the temperature of the object.

Wavelength

Which of the following determines the color of visible light?

Wavelength frequency

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

According to the classical distinction between waves and matter; _______ will bend around edges of a small opening in an object in their path. _______ will go bounce off an object in their path or go straight through.

Waves; particles

An orbital with l = 2 is called a _____ orbital. These orbitals always occur in groups of _____ orbitals of equal energy.

d 5

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.

nm λ

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

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

Which of the following correctly depict the symbol and units for frequency?

v Hz