Exam 2 (Chapter 3-4) Flashcards
(182 cards)
1
Q
What is emitted from the sun?
A
Energy
1. Ultraviolet
2. Infrared
3. Visable light radiation
2
Q
Why does the exposure from the Sun cause damage?
A
Our skin and eyes are sensitive to the photons in UV light (shorter wavelengths) and is damaged by this form of light
3
Q
What kind of damage can the sun cause?
A
Wrinkled, leathery skin, sunspots (solar lentigines) & cataracts
4
Q
What are some positive effects of the sun?
A
Production of Vitamin D (calcium abosrber)
5
Q
How to convert nm to m
A
nm x 1 x 10^-9m/ 1nm = m
6
Q
Which statement correctly describes the procedure used to predict the ion formed by nonmetal elements in Groups 15, 16, and 17?
A
The nonmetal gains enough electrons to attain the same number as its nearest noble gas.
7
Q
The chemistry of carbon-based compounds is called ______ chemistry.
A
Organic
8
Q
ionic compound
A
- Compounds that contain no molecules.
- Compounds are formed when metals combine with nonmetals.
9
Q
Organic chemistry is _______.
A
the study and production of carbon-containing compounds
10
Q
Covalent vs. Ionic bonds
A
- Covalent bonds - attraction between two nuclei and a shared pair of electrons
- Ionic bonds - attraction between oppositely charged ions
11
Q
Which of the following options correctly describe how to name an ionic compound?
A
“metal cation” + “nonmetal anion–ide suffix”
12
Q
Which human activity has the GREATEST net effect on atmospheric CO2 levels?
A
Burning fossil fuels
13
Q
Chemists use the _____ as a unit of amount of substance.
A
Mole
14
Q
Which statement correctly describes the procedure used to predict the ion formed by a main-group element?
A
A metal loses enough electrons to attain the same number as its nearest noble gas.
15
Q
When naming an ionic compound, the _____ is always named first. To name the anion, the root of the nonmetal name is added to the suffix _____.
A
cation; -ide
16
Q
The molar mass of any substance is the mass of 1 ____ of the particles of that substance.
A
Mole
17
Q
Which of the following can be attributed to the atmosphere of planet Earth?
A
The Earth’s average temperature is higher than expected when considering its distance from the Sun.
18
Q
One ____ of any substance contains Avogadro’s number of particles.
A
Mole
19
Q
Which of the following options correctly describes the underlying principle used to determine molecular shape from a Lewis structure?
A
Each group of outer electrons around a central atom is located as far from the others as possible.
20
Q
Correctly order the steps required to determine the shape of a molecule, starting with the first step at the top of the list.
A
- determine the number of outer electrons associated with each atom in the molecule
- arrange the outer electrons in pairs, ensuring that all atoms other than hydrogen obey the octet rule
- determine the shape of the molecule by examining the position of the bonding and nonbonding electron pairs with respect to each other
21
Q
Both Venus and Earth have higher average surface temperatures than expected because _____.
A
both planets have atmospheres that trap radiation
22
Q
Match each labeled bond in the wedge-dash representation shown to its correct meaning.
A
A - in the plane of the page
B - in front of the plane of the page
C - behind the plane of the page
23
Q
The natural process by which Earth’s atmospheric gases trap the infrared radiation radiated by Earth is called the _____ effect. This causes Earth’s average surface temperature to be _____ than that predicted when considering the distance of the Earth from the Sun.
A
greenhouse; higher
24
Q
The most electronegative element is _______
A
fluorine
25
The most stable molecular arrangement is the one in which the ____ electron groups are as far apart as possible, to minimize electron-electron ____.
Outer; interaction
26
What describe the steps required to determine the shape of a molecule?
1. The Lewis structure of the molecule must be drawn first.
2. Both bonding and nonbonding electron pairs must be considered.
3. The shape of the molecule is dictated by the most stable arrangement of the outer electron pairs.
27
Weather vs. climate
Weather - describes events of relatively short duration, including daily high and low temperatures.
Climate - describes regional events recorded over longer periods.
28
What conclusions were reached by the IPCC (International Panel on Climate Change)?
* The average global temperature of the Earth is increasing.
* Human activities play an important role in climate change.
* The burning of fossil fuels has a major impact on climate change.
29
Which of the following options correctly describe variations in solar irradiance and its effect on Earth's climate?
* Changes in the Earth's orbit can affect the amount of solar radiation that reaches the Earth.
* Seasonal variations in sunlight intensity affect local temperatures significantly.
30
Electronegativity generally increases _______ on the periodic table, excluding noble gases.
up and to the right
31
Greenhouse gases have a _____ effect on global warming than other anthropogenic forcings.
Greater
32
Which of the following options correctly describes the underlying principle used to determine molecular shape from a Lewis structure?
Each group of outer electrons around a central atom is located as far from the others as possible.
33
The proportion of incoming radiation that is reflected by a surface is called the ________. This quantity is a measure of the reflectivity of a surface.
Albedo
34
An estimate of the amount of CO2 and other greenhouse gas emissions produced by an individual in a given time frame is referred to as that individual's carbon
footprint
35
What was the role of the IPCC (International Panel on Climate Change), established in 1988?
The IPCC was to assess both scientific and socioeconomic data relating to climate change.
36
Sunspots typically occur about every _____.
11 years
37
What correctly describe albedo?
* The albedo of the Earth affects global temperatures.
* A more reflective surface will have a higher albedo than a less reflective one.
* Albedo is the fraction of incoming radiation that is reflected by a surface.
38
What is meant by the term "carbon footprint" when applied to an individual?
An estimate of the amount of CO2 and other greenhouse gas emissions produced by the individual in a given time frame
39
An estimate of the biologically productive space necessary to support a particular standard of living is called a(n) _____.
ecological footprint
40
The proportion of incoming radiation that is reflected by a surface is called the ____. This quantity is a measure of the reflectivity of a surface.
Albedo
41
When a molecule absorbs an infrared photon it contributes to the ________energy of that molecule.
vibrational
42
Which atom in a molecule of CH3Cl would contain the partial negative charge? (this relates to electronegativity)
chlorine
43
As the wavelength of light descreases (gets shorter) what happens to the frequency of that light?
It increase
44
What can cause electrons in a ground state to go to a higher level excited state?
Photon absorption
45
Any bond that involves the sharing of two electrons is know as an
Covalent bond
46
In reference to waves, frequency is the
Number of waves passing a fixed point in one second
47
Single bonds, double bonds, and triple bonds have how many electrons
Single = 2
Double = 4
Triple = 6
48
Which region of the ultraviolet spetrum is absorbed least by the atmosphere
UV-A
49
How do mineral nanoparticles in sunscreens protect from UV radition?
The particles absorb incoming UV light
50
How to find Molar Mass of a compound C4H8N2O2
1. FInd number of atoms of each element
2. Multiply atomic weight with number of atoms
3. Add them all up
116.12 g/mol
51
What shape would a molecule of carbon tetrachloride have
Tetrahedral
52
When a molecules absorbs an infrared photon it contributes to the ____ energy of that molecule
Vibrational
53
What atom in a molecule of CH3Cl would contain the partial negative charge?
Chlorine
54
Substance that dissolves into a solvent
Solute
55
What gas is most important to maintaining the temperature of earth
Water
56
What vibrational mode for carbon dioxide is not expected to contribute to the greenhouse effect?
Vibrations that cancel each other out
57
Which occurences or process are expected to reduce the level of atmospheric carbon?
The growth of trees & Formation of carbonate rock in the ocean
58
What is the effect of absorption of infrared energy on matter
It increases the vibration of chemical bonds
59
What characteristics pertain to the problem of global warming?
1. Possible consequences include altered climate & increased sea level
2. Heat energy radiated by the earth is captured by atmospheric molecules
60
Using a chemical formula how do you calculate the percentage by mass of a element in a compound
Divide the total mass by the mass of the one element
61
Scientits believe they know the avergage global temperature over the last 160,000 years. Which property of the ice core samples from Antaractica provides this information?
The 1H/2H ratio
62
The history of average global temperature for the last 160,000 years is derived from isotopic analysis of ice layers in Antarctica. Scientists study the _____ ratio in ____
1H/2H; H2O
63
How much is one mole
6.02 x 10^23
64
How to name ionic compunds with main group metals
| CaO
Name of cation (metal) + Base name of anion (non-metal)-ide
| Calcium Oxide
65
How to name ionic compunds with transitional metals
| Fe2S3
“metal cation” + (oxidation state of metal as Roman
numeral) + “nonmetal anion–ide suffix”
| Iron (III) sulfide
## Footnote
Charge is the swapped subscripted
66
How to convert Grams to Atoms
| How many oxygen atoms in 225g O2?
1. convert grams to moles
2. Convert from mole to atoms
67
When determining election & molecular geometry what 3 factors do you need
1. # of Electron groups
2. # of Bond pairs
3. # of Lone pairs
68
Molecular and electron geometry are the same when
No lone pairs present
69
Determining frequency of sqectrum with a certain wavelength
| What is frequency of violet light with wavelength of 408nm
Formula = Speed of light/wavelength
| 3.00 x 10^8 m/s
---------------------- = 7.35 x 10^14
408 x 10^-9
70
What is the constant of the speed of light
3.00 x 10^8m/s
71
nm to meters
| 408nm
1 nm = 10^-9m
| 408 x 10^-9m
72
Type of electromagtic radiation from smallest to largest wavelength
Gamma Rays, X-rays, Ultraviolet, visable, infrared, microwave, radio
73
Order electromagnetic radiation from lowest energy to highest energy
1. Radio waves
2. Microwave
3. Infrared
4. UV-Visible
5. X-rays
6. Gamma
74
Ozone in our atmosphere is important becuase it
absorbs some UV radiation
75
HCFCs are a temporary solution to the problem of ozone depletion and will be replaces by____
HFCs
76
The ozone hole is most prominent on the Earth over
Antarcitica
77
The structure of ozone most closely resembles
Bent molecoles with the same length of chemical bonds
78
As the ozone hole gets more pronounced, with time, one expects the incidence of skin cancer to
Increase worldwide
79
When an atom absorbs visible radiation
Electrons jump from lower energy levels to higher energy levels
80
What is special about the South Pole versus the North Pole that leads to ozone depletion only at the South Pole?
Polar stratospheric clouds form almost exclusively at the South Pole.
81
Ozone forms by
Combining an oxygen atom with an oxygen molecule
82
The state of Ozone in the stratosphere
Dynamic steady state
83
UV radiation will dissociate ozone into
A oxygen atom & an oxygen molecule
84
Formula to find wavelength with frequency
| 93.5MHz
3.00 x 10^8ms/Frequency (frequency x 10^6)
| 3.00 x 10^8ms/ (93.5MHZ x 10^6)
85
How to find how many atoms are in a molecule
| HFC-32
Take number and add 90
| 32 + 90 = 112
1 carbon
2 Fluorine
2 Hydrogen
86
How to convert nm to meters
| 0.002
nm x 10^-9
| 0.002 x 10^-9 = 2 x 10^-12
87
If you have an Avogadro's number of an element and want to find grams of that element
| Avogadro's number of Nitrogen atoms
number of molcules x atomic mass
| 1 x 14.01 = 14.01
88
What shape does a H2O molecule have
Bent
89
Calculating mass of a element in a compound
| O in CO2
element molar mass x subscript/ total molar mass = ___ x 100 =
| 15.999 x 2 / 44.009 = 0.727 x 100 = 72.7
90
How to find mass of an atom of a element
| 1 atom of Au (Gold)
Molar mass of element / Avogadro's number
| 196.96 x 6.02 x 10^23
91
Avogadro's number
6.02 x 10^23
92
Order of radiative forcings that influence the Earth's incoming and outgoing radiation from cooling to warming
1. Smoke, soot, and sulfate aerosols from coal combustion
2. Fresh snow in winter
3. Increased sunspots
4. Halocarbons (CFCs & HCFCs) in atmosphere
93
Vibrationals of molcules absorb infrared radiation when
They are pulled in same direction
94
What substances are regulated by the Kyoto protocol
1. Carbon dioxide
2. Nitrous oxide
3. Sulfur hexafluoride
95
What are consequences of increased carbon dioxide in the atmosphere
* Sea ice disappearance
* sea level rise
* Changes in ocean chemisty
96
What pratices are described as carbon sequestration
Planting trees & Pumping carbon dioxide deep into the ocean
97
Identify possible consequences of global warming.
* A rise in sea level
* An increase in average relative humidity
* An increase in forest growth in the Northern Hemisphere
* A weakening of ocean currents
98
Ozone vs. Oxygen
1. Oxygen - no odor, necessary for life
2. Ozone - Sharp odor, more reactive, harmful air pollutant, protect us from harmful ultraviolet rays
99
What types of radiation does ozone absorb
1. UVB
2. UVC
100
Dobson unit
measures ozone in a column above a specfic location on Earth.
101
Most energetic photons correspond to what wavelengths
Shortest wavelength = 400 nm
102
Ground-level vs stratosphere ozone
Ground level = harmful air pollutant
Stratosphere = benefical to absorb UV-B
103
How does solar UV radiation form a ozone layer
1. The air in the stratosphere is very then
2. UVC splits oxygen moles O2 into 2 oxygen atoms O
* W/O UVC light ozone layer won't form
3. They react with other oxygen molecules to produce ozone O3
104
Wavelength
Distance traveled between successive peaks (nm)
105
Frequency
Number of waves passing a fixed point in 1 second (waves/s or 1/s or s^-1 or Hz)
106
Equation for wavelength & frequency relation
Frequency = C (speed of light) /Wavelength
107
Distribution of energy from the sun to earth
53% infrared radiation (heat), 39% visible light, & 8% UV
108
Types of UV radiation
109
What photon wavelength is required to break O2 and O3
O2 = photons with wavelengths <242nm UVC
O3 = Photons with wavelengths <320nm UVB
110
What happens when UV radiation is absorbed by skin
Lower energy UVA light removes electrons from molecules such as water, creating free radicals & other reactive oxygen species
111
Higher-energy UVB light causes
Some chemical bonds to break
112
Damaged DNA molecules by free radicals or UVB aborption causes
The release of melanin
113
Melanin
Provide skin color and protects skin from skin cancer
- White men
- White women
- Black men
- Black women
114
Biological effects of UVC exposure
Highly energetic and absorbed completely by oxygen moles
115
Biological effects of UVB exposure
* Partially absorbed by ozone in the stratosphere
* Some reaches Earth’s surface where it is rapidly absorbed at the surface of skin.
116
Biological effects of UVA exposure
* UVA is not absorbed by the atmosphere.
* Less energetic than UVB = penetrates deeper into skin, causing more damage to underlying tissue.
117
Skin cancer most common in
Older white males
118
What radiation is linked with skin cancers
* UVA = mostly
* UVB = may play a role
119
What skin cells does cancer arise in
1. Basal & squamous cell = common but seldom fatal
2. melanocyte cell (melanomas) = most deadly
120
Pros and cons of UV exposure
Pro = needed for production of vitamin D
Con = Too much leads to cancers & eye disease
121
UV-Index
color-coded UV index scale is used to predict the risk of sunburn from overexposure to UV light from the Sun
122
Factors that UN index uses to forecast
1. Ozone concentration in upper atmosphere
2. elevation
3. cloud cover
123
Ozone layer
Region in the stratosphere with maximum ozone concentration (12,000 ppb)
124
How is Ozone concentration measured
Ozone concentration of 100 Dobson units (DU) = 3mm
125
How to make Lewis Structures
1. Count number of outer electrons (“valence electrons”) contributed by each atoms in the molecule.
2. Add the valence electrons contributed by individual atoms
3. Arrange the valence electrons in pairs.
4. Distribute valence electrons to maximize stability by giving each atom a share in enough electrons to fully fill its outermost energy level (2 electrons for hydrogen; 8 electrons for most other atoms).
126
The Chapman Cycle
Set of reactions that occur natturally in upper atmosphere that result in a stead-state concentration of ozone in the stratosphere
127
ozone can be naturally destroyed by
Dissociation of water molecules into free radicals (H & OH)
128
Chlorofluorocarbons (CFCs)
Pros = nontoxic, nonflammable, inexpensive, & widely avaliable (used in AC)
Con = Destroys ozone through series of reactions - moles break apart by UVC radiation in upper atmosphere
129
What is the coldest spot on Earth
Lower stratosphere over south pole -- where Stratospheric clouds (PSCs) occur
130
Polar stratospheric clouds (PSCs)
helps support the chemical reactions that produce active chlorine that catalyzes ozone destruction
131
1987 Montreal protocol
## Footnote
recovery of ozone with atmospheric chlorine concentrations return to 1980 levels in Antarctica the year 2070.
Caused the production of CFCs to plummet
132
Alternatives to CFC
Hydrofluorocarbons (HFCs)
133
Hydrofluorocarbons (HFCs)
replace chlorine(s) with hydrogen(s) to prevent the release of atomic chlorine, which catalyzes ozone destruction. HFCs still greenhouse gas
134
How does sunscreen work
unscreens contain nanoparticles of zinc oxide (ZnO) or titanium oxide (TiO2), which are able to absorb radiation of certain wavelengths.
135
Electrons when energy is absorbed
electrons are promoted from
lower-energy states into excited
states.
136
Sunscreen with organic-based compounds (primarily composed of carbon, hydrogen, and oxygen) capable of
absorbing UVA and/or
UVB radiation.
137
three main reservoirs for
carbon:
1. Atmosphere = in form of carbon dioxide & cardon monoxide
2. Carbonate-containing rocks, fossil fuels, & soils
3. Plants and animals = carbon atoms combine with oxygen, hydrogen, & nitrogen to form carbohydrates, proteins, & lipids
138
The carbon cycle
global carbon cycle shows the quantities of carbon (in gigatonnes) that are stored in various carbon reservoirs (black) or moving through the system per year (red).
139
Global carbon dioxide emissions
26% = power/heating stations
19% = Industry
17% = Deforestation
13% = Transportation
14% = Agriculture
8% = Residential/ commercial buildings
3% = waste & wastewater
140
ionic compound
contains both a metal and nonmetal in
its chemical formula.
| Carbon found in rocks
141
Atomic mass
the weighted average of
their naturally occurring isotopes.
142
carbon atomic mass
12.011
143
Mass number
number of neutrons + number of protons
144
Isotopes have
equal numbers of protons, but different amounts of neutrons
145
Mole
| 1 mol C = 12.01 g
has a mass (in grams) equal to the atomic mass of the element in unified atomic mass units, u.
146
Converting grams to moles
147
1 mole of anything equals
6.02 x 10^23 (Avogadro’s number).
| 1 mole of carbon = 6.02 x 10^23 (Avogadro’s number).
148
How to calculate molar mass
| 1 mole of NaCl
adding up the atomic masses for the different types of atoms.
| 22.99 g/mol (sodium) + 35.45 g/mol (chlorine) = 58.44 g
149
How to calculate carbon dioxide emissions
| How much carbon dioxide is produced from burning 3.3 Gt of carbon
150
How to calculate molecules in carbon dioxide emissions
| How many molecules of Carbon Dioxide are in 12 Gt
151
Where does the sun's radiation go
46% = absorbed by Earth
54% = absorbed in atmosphere or reflected from Earth's surface or atmosphere
152
What happens to radiation absorbed by Earth
37% = remitted in form of Infrared (IR) radiation
Causes greenhouse effect
153
“Greenhouse Effect” Average temperature
15 C (59 F)
154
Without Earth's energy Balance
average temperature of Earth would be -18C (0F) and the oceans would be frozen year round
155
80% of infrared radiation emitted by Earth is absorbed by
atmospheric gases
156
absorption of infrared radiation causes
molecular vibrations such as bending and
stretching
157
How to predict molecular shape
1. Detemine number of valence electrons for each atom in molecule
2. Draw lewis structure
3. Assume most stable molecular shape has the bonding electron pairs as far apart as possible.
4.
158
lone pairs
the central atom in a molecule may
have non-bonding electron pairs
159
lone pair occupies
a greater space than a bonding electron pair, which influences the final shape of the molecule.
| ammonia (NH3)
160
Linear
molecules with 2 atoms bonded to a central atom, if there are no lone pairs on the central atom.
161
Linear
molecules with 2 atoms bonded to a central atom, if there are no lone pairs on the central atom.
| Carbon Dioxide
162
Bent
| Water & ozone
If there are at least one lone pair on the central atom
| bent = minimize the repulsion between lone pair & bonding electrons.
163
Infrared radiation causes
molecular vibrations of stretching
and bending
164
Microwave radiation causes
molecular rotations
165
Electronegativity
the measure of an atom’s ability to attract bonded electrons.
| the “stronger” atom has a higher electronegativity
166
Electronegativity
the measure of an atom’s ability to attract bonded electrons.
| the “stronger” atom has a higher electronegativity
167
Electronegativity increases from the
bottom-top of a group and left-right across a
period.
| fluorine has greatest electronegativity & cesium has the
lowest value.
168
the more electronegative atom will carry a
artial negative charge (d-)
169
effective absorber of
infrared radiation and is a
greenhouse gas
Water
## Footnote
responsible for maintaining Earth’s temperature is primarily due to water vapor, followed by carbon dioxide.
170
Microscopic air bubbles in ice
core samples from glaciers can be
used to
determine changes in
greenhouse gas concentrations
over time.
171
The current
concentration of atmospheric
carbon dioxide is
about 100 ppm
higher than any time in the last
million years
172
concentration of carbon
dioxide and the global
temperature are
correlated over the past 400,000
years as derived from ice core
data.
173
What amplifys natural greenhouse effect
1. CO2 contributes to an elevated global temperature.
2. The concentration of CO2 in the atmosphere has been increasing over the past century.
3. The increase of atmospheric CO2 is a consequence of human activity.
4. The average global temperature has increased over the past century.
174
What may amplify greenhouse gases effect in future
1. Carbon dioxide and other gases generated by human activity are responsible for the temperature increase.
2. The average global temperature will continue to rise as
emissions of anthropogenic greenhouse gases increase.
175
Radiative forcings
factors that affect the balance of Earth’s incoming and outgoing radiation
176
Radiative forcings
factors that affect the balance of Earth’s incoming and outgoing radiation
177
greatest warming effects are
found for Greenhouse gases of
1. carbon dioxide
2. water
3. methane
4. chlorofluorocarbons
5. hydrofluorocarbons
6. dinitrogen monoxide
178
Climate models show
natural factors have influenced this temperature change BUT man-made (anthropogenic) factors also play an important role
179
Intergovernmental Panel on Climate Change key points
1. Human influence on Earth’s climate is clear, and human caused emissions of greenhouse gases are the highest in history
2. Human activities (primarily the combustion of fossil fuels and deforestation) are responsible for atmospheric and ocean warming, lower concentrations of ice and snow on the planet, and sea level rise
3. Continued emission of greenhouse gases will result in further warming and long-lasting change in Earth’s climate system. This will cause an increased likelihood of severe, pervasive, and irreversible impacts for both ecosystems and people.
180
As the oceans warm and ice thins, more solar energy is
absorbed by the water, creating positive feedbacks that lead to further melting.
181
The Intergovernmental Panel on Climate Change (IPCC) certified
the
scientific basis of the greenhouse effect.
182
The Kyoto Protocol (1997) established
goals to stabilize and reduce
atmospheric greenhouse gases.
