Chapter 4 Review

Question 1

a. Five examples of electromagnetic radiation

b. what is the speed of all forms of electromagnetic radiation in a vacuum?

Answer 1

a.
1. X-rays
2. Ultraviolet light
3. Infrared light
4. Microwaves
5. Radio waves
b. 3.0 x 10^8 m/s

Question 2

Properties of light that can best be explained by wave theory vs. particle theory

Answer 2

1. Wave theory
   
   • Measurable r+v (figure out what this is) + (the velocity of the wave)
   • Interference diffraction
2. Particle Theory
   
   • Photoelectric effect
   • Emission of light by hot objects
   • Line emission spectrum of elements

Question 3

What are the frequency and wavelength ranges of visible light?

Answer 3

400nm - 700nm

Question 4

What is the order of visible colors from left to right?

Answer 4

Purple, blue, green, yellow, orange, and red

Question 5

In the early 20th century, what two experiments, involving light and matter, couldn’t be explained by the wave theory of light?

Answer 5

• Hydrogen-atom emission line spectrum

- Photoelectric effect

Question 6

a. How are wavelength and frequency of electromagnetic radiation related?
b. How are the energy and frequency of electromagnetic radiation related?
c. How are the energy and wavelength of electromagnetic radiation related?

Answer 6

c=λv –> energy = (wavelength)(frequency)
a. A wavelength decreases, frequency increases and vice versa.
b. The higher the frequency, the higher the energy
E=hv
c. As wavelength increases, frequency decreases and so does energy.

Question 7

Theory of light that best explains these phenomena:

a. the interference of light
b. the photoelectric effect
c. the emission of electromagnetic radiation by an excited atom

Answer 7

a. wave theory
b. particle theory
c. wave theory

Question 8

What is ground state?

What is excited state?

Answer 8

• ground state is the lowest energy state an electron can have
• excited state is when an electron absorbs energy and moves up to a higher energy state

Question 9

According to Bohr’s model of the hydrogen atom, how is hydrogen’s emission spectrum produced?

Answer 9

It’s produced when an electron from a higher energy orbit drops down to a lower level energy orbit.

Question 10

Determine the frequency of light whose wavelength is 4.257 x 10^-7 cm

Answer 10

c = λv

3. 00 x 10^8 = (4.257 x 10^-7 m)v
4. 05 x 10^14 = v

Question 11

Determine the energy in joules of a photon whose frequency is 3.55 x 10^17 Hz

Answer 11

E = hv
E = (6.620 x 10^-34 JS)(3.55 x 10^17 /s)
E = 2.35 x 10^-10 J

Question 12

Using the equations E = hv and c = λv, derive an equation expression E in terms of h, c, and λ.

Answer 12

E = hv and c = λv
E = (hc)/λ

Question 13

Cobalt-60 is an artificial radioisotope that is produced in a nuclear reactor and is used as a gamma ray source in the treatment of certain types of cancer. If the wavelength of the gamma radiation from a cobalt-60 source is 1.00 x 10^-3 nm, calculate the energy of a photon of this radiation.

Answer 13

c = λv --> v = λc
v = (1.00 x 10^-3 nm)(3.00 x 10^8 m/s)
v = 3.00 x 10^21 (input the proper variable thing)

E v(photon) = hv
E v(photon) = (6.626 x 10^-34)(3.00 x 10^21)
E v(photon) = 1.9878 x 10^-12
E v(photon) = 1.99 x 10^-12 (input the proper variable thing)

Question 14

What were the two major shortcomings of Bohr’s model of an atom?

Answer 14

• didn’t explain the spectra of atoms with more than one electron
• didn’t explain the chemical behavior of atoms

Question 15

a. what is the principal quantum number?
b. how is it symbolize?
c. what are shells?
d. How does n relate to the number of electrons allowed per main energy level?

Answer 15

a. n
b. the main energy level being occupied by the electron
c. energy levels
d. n^2 is the same as the total number of orbitals that exist in the main energy level

Question 16

a. what information is given by the angular momentum quantum number?
b. what are sublevels, or subshells?

Answer 16

a. shape of the orbital

b. energy levels defined by quantum theory

Question 17

indicate the numbers and types of sublevels possible for each main energy level:

a. n=1
b. n=2
c. n=3
d. n=4
e. n=7

Answer 17

a. 1 possible sublevel – s orbital
b. 2 possible sublevels – s and p orbitals
c. 3 possible sublevels – s, p, and d orbitals
d. 4 possible sublevels – s, p, d, and f orbitals
e. 7 possible sublevels

Question 18

a. what information is given by the magnetic quantum number ?
b. how many orbital orientations are possible in if the s, p, d, and f sublevels?
c. Explain and illustrate how to distinguished between the different p orbitals in a sublevel?

Answer 18

a. orientation/location of an orbital around the nucleus
b. s → 1 possible orientation
p → 3 possible orientations
d → 5 possible orientations
f → 7 possible orientations
c. There are three p orbitals: px,; py; pz (x, y, and z are ^ to p, but in the opposite direction, like v direction) LOOK IN PAPER REVIEW FOR DRAWING (Q#19)

Question 19

a. What is the relationship between “n” and the total number of orbitals in the main energy level?
b. how many total orbitals are contained in the 3rd and the 5th main energy level?

Answer 19

a. as n increases, so does the total number
b. total of 9 orbitals in the 3rd main energy level
total of 25 orbitals in the 5th main energy level

Question 20

a. what information is given by the spin quantum number?

b. What are the possible values for this quantum number?

Answer 20

a. fundamental spin state of an electron in an orbital

b. +1/2 and -1/2

Question 21

How many electrons can be contained in the following main energy levels with n equal to the number provided?
n=1
n=3
n=4
n=6
n=7

Answer 21

n = 1 → 2
n = 3 → 18
n = 4 → 32
n = 6 → 72
n = 7 → 98

Question 22

draw the s and the p orbital

Answer 22

LOOK AT PAPER REVIEW FOR DRAWING (Q#23)

Question 23

how are the 1s and the 2s orbitals different?

Answer 23

2s has an extra node

Question 24

what’s different between 2px and 2py?

Answer 24

2px is on the x-axis, 2py is on the y-axis

Question 25

a. what is the Aufbau Principle? | b. Explain the meaning of the principle in terms of an atom with many electrons.

Answer 25

a. an electron will always fill up the lowest energy level possible b. in atoms with a lot of electrons, electrons fill up an entire orbital level, before any electrons go into the orbital above it

Question 26

a. What does Hund's rule say? | b. What is the basis for this rule?

Answer 26

a. Hund's rule says that all orbitals with equal energy levels have to have one electron, before a second electron enter any of the orbitals b. to minimization of electron-electron repulsion, which lets electron arrangements have the lowest possible energy

Question 27

a. what does the Pauli Exclusion Principle say? | b. what is the significance of the spin quantum number?

Answer 27

a. it's not possible for two electrons in the same atom to have the same set of four quantum numbers b. for two electrons to occupy the same orbital, they have to have opposite spin states

Question 28

a. what is it meant by the highest occupied energy level in an atom? b. what are inner shell electrons?

Answer 28

a. highest principal quantum number | b. all electrons not in the principal quantum number

Question 29

Determine the highest occupied energy level in the following elements: a. He b. Be c. Al d. Ca e. Sn

Answer 29

``` He → 1 Be → 2 Al → 3 Ca → 4 Sn → 5 ```

Question 30

Write the orbital notation for P, B, Na, and O

Answer 30

LOOK AT PAPER REVIEW SHEET (Q.#31)

Question 31

Write the electron-configuration notation for the elements whose atoms contain the following number of electrons: a. 3 b. 6 c. 8 d. 13

Answer 31

a. 3 → 1s^2 2s^1 b. 6 → 1s^2 2s^2 2p^2 c. 8 → 1s^2 2s^2 2p^4 d. 13 → 1s^2 2s^2 2p^6 3s^2 3p^1

Question 32

Oxygen: a. number of electrons? b. atomic number? c. orbital notation? d. number of unpaired electrons? e. highest occupied energy level? f. number of inner shell electrons? g. where are its inner shell electrons?

Answer 32

a. 8 b. 8 c. LOOK AT PAPER REVIEW SHEET d. 2 e. p f. 2nd main energy level g. 1s

Question 33

a. What are noble gases? b. What is noble-gas configuration? c. How does noble-gas notation simplify writing an atom's electron configuration?

Answer 33

a. nonreactive elements; group 18 b. start with the elemental symbol of the last noble gas prior to that atom, continue with the configuration of the remaining electrons c. it is implied that all of the noble gas' configuration is included so it simplifies the element's own electron-configuration notation

Question 34

Write the noble-gas notation for the electron configuration of each of the elements below: a. Cl b. Ca c. Se?

Answer 34

a. Cl → [Ne] 3s2 3p5 b. Ca → [Ar] 4s2 c. Se → [Ar] 4s2 3d10 4p4

Question 35

a. What information is given by the noble-gas notation [Ne]3s^2? b. What elements does this represent?

Answer 35

a. [Ne]3s^2 shows that the element is on the Period 3, after the noble gas Ne, and in Group 2. b. [Ne]3s^2 represents Mg.

Question 36

Write the electron-configuration notation and the noble-gas configuration of Na, Sr, and P.

Answer 36

``` Na → - 1s^2 2s^2 2p^6 3s^1 - [Ne] 3s^1 Sr → - 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 - [Kr] 5s^2 P → - 1s^2 2s^2 2p^6 3s^2 3p^3 - [Ne] 3s^2 3p^3 ```

Question 37

Identify each of the following atoms on the basis of its electron configuration: a. 1s^2 2s^2 2p^1 b. 1s^2 2s^2 2p^5 c. [Ne] 3s^2 d. [Ne] 3s^2 3p^2 e. [Ne] 3s^2 3p^5 f. [Ar] 4s^1 g. [Ar} 3d^6 4s^2

Answer 37

a. Boron b. Fluorine c. Magnesium d. Silicon e. Chlorine f. Potassium g. Calcium

Question 38

List the order in which orbitals generally fill, from the 1s to the 7p orbital.

Answer 38

1s - 2s - 3s - 3p - 4s - 3d - 4p - 5s - 4d - 5p - 6s - 4f - 5d - 6p - 7s - 5f - 6d - 7p

Question 39

Write the noble-gas notation for the electron configurations of the following elements: a. As b. Pb c. Lr d. Hg e. Sn f. Xe g. La

Answer 39

a. As → [Ar] 4s^2 3d^10 4p^3 b. Pb → [Kr] 5s^2 4d^10 5p^6 6s^2 4f^14 5d^10 6p^2 c. Lr → [Rn] 7s^2 5f^14 d. Hg → [Xe] 6s^2 4f^14 5d^10 e. Sn →[Sn] 5s^2 4d^10 5p^2 f. Xe → [Kr] 4d^10 5s^2 5p^6 g. La → [Xe] 6s^2 4f^14 5d^1

Question 40

How doe the electron configurations of chromium and copper contradict the Aufbau Principle?

Answer 40

In Chromium, each 3d orbital gets 1 electron before any 4s orbital gets a second electron In Copper: every 3dorbital gets 2 electrons before any 4s orbital gets a second electron.

Question 41

a. which has a longer wavelength: green light or yellow light? b. which has a higher frequency: an X ray or a microwave? c. which travels at a greater speed: ultraviolet light or infrared light?

Answer 41

a. yellow has a longer wave length b. x rays have a higher frequency c. ultraviolet light travels faster

Question 42

Write the electron-configuration notation and the noble-gas configuration of Ar, Br, and Al.

Answer 42

``` Ar → - 1s^2 2s^2 2p^6 3s^2 3p^6 - [Ne] 3s^2 3p^6 Br → - 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^5 - [Ar] 4s^2 3d^10 4p^5 Al → - 1s^2 2s^2 2p^6 3s^2 3p^1 - [Ne] 3s^2 3p^1 ```

Question 43

given the speed of light as 3.00 x 10^8 m/s, calculate the wavelength of the electromagnetic radiation whose frequency is 7.500 x 10^12 Hz?

Answer 43

``` c = vλ → λ = c/v λ = (3.00 x 108 m/s) / (7.500 x 1012 hz) λ = 4 x 105 m ```

Question 44

a. what is the electromagnetic spectrum? b. what units can be used to express wavelength? c. what units can be used to express frequencies of electromagnetic waves?

Answer 44

a. the range of wavelengths and frequencies that electromagnetic radiation, or light, extend b. meter (m) c. hertz (hz)

Question 45

Phosphorus: a. number of electrons? b. atomic number? c. orbital notation? d. number of unpaired electrons? e. highest occupied energy level? f. number of inner shell electrons? g. where are its inner shell electrons?

Answer 45

a. 15 b. 15 c. LOOK AT PAPER REVIEW d. 3 e. 3rd main energy level f. 10 inner shell electrons g. 1s, 2s, and 2p

Question 46

What is the frequency of a radio wave whose energy is 1.55 x 10^-24 J per photon?

Answer 46

Ephoton = hv 1.55 J per photon = (6.626 x 10-34) v v = (1.55 J per photon) / (6.626 x 10-34) v = 2.34 x 1033 hz

Question 47

Write the noble-gas notation for the electron configurations of the following elements: a. Hf b. Sc c. Fe d. At e. Ac f. Zn

Answer 47

a. Hf → [He] 6s^2 4f^14 5d^2 b. Sc → [Ar] 4s^2 3d^1 c. Fe → [Ar] 4s^2 3d^6 d. At → [Xe] 6s^2 4f^14 5d^10 6p^5 e. Ac → [Rn] 7s^2 5f^14 6d^1 f. Zn → [Ar] 4s^2 3d^10