Chapter 7

In general terms, why do we call light electromagnetic radiation?

In general, what does the term frequency imply? What is meant by the term frequency of light? What symbol is used for it, and what is the SI unit (and symbol) for frequency?

What is meant by the term wavelength of light? What symbol is used for it?

Sketch a picture of a wave and label its wavelength and its amplitude. Indicate how frequency could be measured.

Which property of light waves is a measure of the brightness of the light? Which specifies the color of the light? Which is related to the energy of the light?

What wavelength range is covered by the visible spectrum?

Arrange the following colors of visible light in order of increasing wavelength: orange, green, blue, yellow, violet, red.

What is the equation that relates the wavelength and frequency of a light wave? (Define all symbols used.)

How is the frequency of a particular type of radiation related to the energy associated with it? (Give an equation, defining all symbols.)

Show that the energy of a photon is given by the equation $$ E=\frac{h c}{\lambda} $$

Examine each of the following pairs and state which of the two has the higher energy: (a) microwaves and infrared, (b) visible light and infrared, (c) ultraviolet light and \(\mathrm{X}\) rays, (d) visible light and ultraviolet light.

What is an atomic spectrum? How does it differ from a continuous spectrum?

What fundamental fact is implied by the existence of atomic spectra?

Describe Niels Bohr's model of the structure of the hydrogen atom.

In qualitative terms, how did Bohr's model account for the atomic spectrum of hydrogen?

Why does the equation for the energy of an electron in a Bohr atom have a negative sign?

What is the difference between a traveling wave and a standing wave?

What are the names used to refer to the theories that apply the matter-wave concept to electrons in atoms?

What is the term used to describe a particular waveform of a standing wave for an electron?

What information does each type of quantum number give for an atomic orbital?

Why is (a) the \(d\) subshell in the Period 4 designated as \(3 d\) and \((\mathbf{b})\) the \(f\) subshell in Period 7 designated as \(5 f ?\)

Why does every shell contain an \(s\) subshell?

How many orbitals are found in (a) an s subshell, (b) a \(p\) subshell, (c) a \(d\) subshell, and (d) an \(f\) subshell?

What is the Pauli exclusion principle? What effect does it have on the populating of orbitals by electrons?

What are the possible values of the spin quantum number?

What is the "ground state" of an atom?

Within any given shell, how do the energies of the \(s, p, d\), and \(f\) subshells compare? How do the energies of the orbitals belonging to a given subshell compare?

Give the electron configurations of the elements in Period 2 of the periodic table.

Using your own words, describe how to use the periodic table to write the electron configuration of an element.

Give the correct electron configurations of (a) Cr and (b) Cu. Explain why they do not have the expected electron configurations.

How are the electron configurations of the elements in a given group similar? Illustrate your answer by writing shorthand configurations for the elements in Group \(6 \mathrm{~A}\).

Define the terms valence shell and valence electrons. Define core electrons.

Why do we use probabilities when we discuss the position of an electron in the space surrounding the nucleus of an atom?

Sketch the approximate shape of (a) a \(1 s\) orbital and (b) a \(2 p\) orbital.

How does the size of a given type of orbital vary with \(n\) ?

How are the \(p\) orbitals of a given \(p\) subshell oriented relative to each other?

What is a nodal plane? How are the number of nodal planes relate to the value of \(\ell\) ?

What is a radial node? How are the number of radial nodes related to the value of \(n\) and \(\ell\) ?

How many nodal planes does a \(p\) orbital have? How many does a \(d\) orbital have?

On appropriate coordinate axes, sketch the shape of the following \(d\) orbitals: \(\left(\right.\) a) \(d_{x y},\) (b) \(d_{x^{2}-y^{2}},\) (c) \(d_{z^{2}}\).

What is the meaning of effective nuclear charge? How does the effective nuclear charge felt by the outer electrons vary going down a group? How does it change as we go from left to right across a period?

Explain why a \(3 s\) electron in Al experiences a greater effective nuclear charge than a \(3 p\) electron. Atomic Size

Explain why the atomic size varies across the periodic table and down the periodic table.

Explain why cations are smaller than their uncharged atoms and anions are larger than their uncharged atoms.

In what region of the periodic table are the largest atoms found? Where are the smallest atoms found?

Going from left to right in the periodic table, why are the size changes among the transition elements more gradual than those among the representative elements?

Define ionization energy. Why are ionization energies of atoms and positive ions endothermic quantities?

For oxygen, write an equation for the change associated with (a) its first ionization energy and (b) its third ionization energy.

Explain why ionization energy increases from left to right in a period and decreases from top to bottom in a group.

Why is an atom's second ionization energy always larger than its first ionization energy?