chem radiation from the sun

light travels through a particular type of glass at a speed of 2.2x10^8m/s. which of the following options show the correct procedure to convert this quantity to units of miles per hour (mi/hr or mph), given that 1 mile is equal to 1609 meters?

(2.2x10^8 m/s) x (3600 s/hr)= 4.5x10^8 mi/hr

T/F: Resonance forms are different possible structures for the same species that interconvert rapidly.

False. No individual resonance form actually exits and there is no interconversion between forms. Rather the true structure is a single structure that is an average of all possible resonance forms.

mineral- based sunblock preparations may contain --. Select all that apply.

ZnO TiO2

Which of the following options correctly describes the unique conditions in the Antarctic that cause the region to have disproportionately large hope in the ozone layer?

- Temperatures are as cold as -90C -winds in the area form a vortex that prevents warmer air from entering the Antarctic - Polar stratospheric clouds formed in this region initiate reactions of benign species to more reactive species

Which of the following statements correctly describe the origin and uses of CFC's

1. CFCs are inert and nontoxic 2. CFCs are very chemically persisted molecules

Draw the Lewis structure for the covalent molecule CCl4. Which of the following statements correctly describes the Lewis structure of CCl4?

1. The lewis structure of CCI4 contains four single bonds 2. the lewis structure of CCI4 contains 12 lone pairs

rank the three types of UV radiation in order of increasing wavelength, starting with the shortest wavelength radiation at the top of the list

1. UV-C 2. UV-B 3. UV-A

place the steps taken to reduce the depletion of the ozone layer in chronological order, starting with the first step at the top of the list

1. United nations environmental programme 2. Vienna convention on the protection of the ozone layer 3. montreal protocol 4. complete stoppage of production of CFC's in developing nations

place the steps for drawing a lewis structure in the correct order, starting with the first step at the top of the list

1. count the number of outer electrons contributed by each atom 2. add the valence electrons contributed by each individual atom 3. arrange the outer electrons in pairs around the contributing atoms 4. ensure that each atom has a full outer shell

Rank the following types of radiant energy in order of increasing frequency.

1. microwave 2. infrared 3. visible 4. ultraviolet

Arrange the following types of radiation in order of increasing energy per photon, starting with the lowest energy radiation at the top of the list

1. radio waves 2. infrared radiation 3. visible light 4. gamma waves

rank the following types of bonds from the longest to the shortest, starting with the longest bond at the top of the list

1. single covalent bond 2. double covalent bond 3. triple covalent bond

a catalyst --. Select all that apply.

1. undergoes no permanent change during a reaction 2. is typically regenerated during the reaction

Place the following types of electromagnetic radiation in order of increasing wavelength (from shortest to longest):

1. x-ray 2. UV radiation 3. visible light 4. IR radiation 5. radiowaves

the covalently bonded species shown has -- shared pair(S) of electrons and -- lone pair(s). . . H>N>H v H

3; 1

atoms bond in order to fill their valance shell of electrons. Most elements strive for a total of -- such electrons while hydrogen strives for a total of --.

8; 2

select the correct symbol and units for wavelength. More than one unit and/or symbol may be correct.

A (the teepee shaped); nm

match each element with the correct number of valence electrons

C - 4 Be- 2 Ne- 8 F- 7

match each type of formula with the correct description

Chemical formula: shows only types and ratios of atoms present structuctural formula: representation of how atoms are arranged, omitting lone pairs of electrons lewis structure: representation of how atoms are connected, including lone pairs of electrons

match each molecule with the correct description of its bonding

H2O2 = the molecule posses no multiple bonds HCN= this molecule possesses one triple bond CS2= this molecule possesses two double bonds

which of the following species cause ozone to break down naturally in the stratosphere? Select all that apply.

H2O; N2O

what type of compound is depicted in the illustration? .. H :Cl: | | .. H- C- C- F: | | .. H :Cl: ..

HCFC

which two types of molecules are potential replacements for CFCs?

HFCs HCFCs

which of the following statements describe the advantages and disadvantages of the replacements for CFCs? select all that apply.

HFCs are nontoxic and nonflammable HFCs are considered greenhouse gases

Which of the following statements correctly describes a Lewis structure? Select all that apply.

Lone pairs are shown as pairs of dots on individual atoms bonding electrons are shown as lines or pairs of dots between two atoms

match each form of oxygen with the wavelength of UV radiation that is sufficient to break its bonds

O3- A<320nm O2- A<242

which of the following statements correctly describe polar stratospheric clouds (PSCs)? select all that apply.

PSCs provide a surface for chemical reactions to occur psc are composed of tiny ice crystals

the process by which green plants convert sunlight into stored chemical potential energy by producing glucose and oxygen is called --.

Photosynthesis

which of the following statements correctly describe natural variations in stratospheric ozone levels? select all that apply.

Ranson fluctuations in ozone concentration The amount of radiation emitted by the sun varies over 11-12 year cycle, which causes variations in ozone production.

match each region of the atmosphere correctly with the abundance of ozone

Troposphere- 100 O3 molecules (upper limit) per billion molecules that make up the air stratosphere- 12,000 O3 molecules (upper limit) per billion molecules that make up the air

which of the following statements correctly describe UV radiation? select all that apply.

UV radiation can cause biological damage photons from UV radiation can displace electrons from neutral molecules creating positively charged species.

match each type of radiation correctly with either its source or its function

UV radiation- this type of radiation is given off by the sun and is harmful to humans x-rays- this type of radiation is used in medical diagnosis and the determination of crystal structures gamma rays- this type of radiation is given off in nuclear decay microwaves-this type of radiation is used to cook food quickly

match each type of formula with the correct representation a: dots b. dash c. exponents

a. Lewis structure b. Structural formula c. chemical formula

Which coefficients are needed to balance the simplified chemical equation representing the formation of ozone? energy+a O2= b O3

a=3; b=2

resonance forms are lewis structures that have the same relative placement of -- but a different arrangement of --.

atoms; electrons

which compound is a CFC or chlorofluorocarbon?

b-Cl,C, F

a nanometer is one -- of a meter

billionth (1 nm= 1x10^-9 m

we describe the "speed of light" as the speed at which light and other forms of radiation travel through a vacuum. This quantity, which is equal to 3.00x10^8 m/s, is given the symbol --.

c

which elements are found in hcfcs? select all that apply.

carbon fluorine chlorine hydrogen

in the destruction of ozone by CFCs chlorine is both consumed and regenerated during the cycle, with no net change in its concentration. Chlorine therefore acts as a(n) -- in the process.

catalyst

chlorfluorocarbons (CFCs) and their replacement compounds (HFCs and HCFCs) have a negative impact on our environment because they all

contribute to global climate change

the bond formed between two nonmetals is called a(n) -- bond. This bond involves the -- of one or more electron pairs between the two atoms.

covalent; sharing

replacing halogen atoms (such as Cl) in CFCs with hydrogen results in a(n) --. select all that apply.

decrease in boiling point decrease in molar mass

one unit used to measure ozone concentration is the -- unit, which is equivalent to 3x10^16 O3 molecules in a vertical column of air with a cross section of 1 cm^2

dobson

which of the following options correctly describe the determination of ozone concentration by measuring UV radiation from the atmosphere? select all that apply.

dobson units are used to quantify the amount of ozone in a column of air the lower the intensity of UV radiation reaching the detector, the greater the concentration of ozone in a column of air

lewis structures are used to represent covalent compounds. Shared electron pairs are shown either as pairs of -- or lines and only -- electrons are shown.

dots; outer

a new technique for monitoring stratospheric ozone is called limb viewing. in this technique --.

equipment aboard a space shuttle "looks" sideways through the thin blue haze above the troposphere

which of the following options correctly describe potential biological effects of UV radiation in addition to skin cancer? select all that apply.

exposure to UV radiation can cause retinal damage Harmful UV radiation could have an effect on the carbon dioxide balance of our planet

what were the most important properties considered when designing a suitable replacement for CFCs? select all that apply.

extreme stability toxicity flammability

CFCs always contain --. Select all that apply.

fluorine chlorine carbon

the -- of a wave is the number of wave cycles per second.

frequency

For the main-group elements (1,2,etc.) the number of valence electrons for an element is equal to the -- number for the element.

group

energy and wavelength are related through the equation: E=hc/^. Match each symbol with the correct identity.

h = Planck's constant c = speed of light E = energy per photon Y = wavelength

Match each prefix or term to its correct meaning when applied to an organic compound

hydro= C-H bonds are present fluoro= C-F bonds are present olefin= C=C double bonds are present

exposure to UV radiation causes the concentration of melanin in the skin to --.

increase

on average, the concentration of ozone -- as one gets closer to either pole, with the exception being the seasonal ozone hole over the --

increases; Antarctic

wavelength and frequency are -- proportional to each other. As wavelength increases frequency will --.

inversely; decrease

the skin pigment responsible for darkening the skin due to UV exposure is called --

melanin

A species such as Cl2 or H2O, in which the atoms are connected by shared electron pairs, is called a(n) --

molecule

which of the following statements correctly describe the natural sources of chlorine? select all that apply.

natural sources of chlorine include seawater and volcanoes HCl is a natural form of chlorine natural chlorine-containing substances are water soluble

what characterizes a free radical?

one or more unpaired electrons

match the molecular formula for each form of oxygen with the correct chemical name.

oxygen-O2 Ozone-O3

A designated region in the stratosphere of maximum O3 concentration is called the -- layer.

ozone

a designated region in the stratosphere of maximum O3 concentration is called the -- layer.

ozone

which of the following statements correctly describe the factors that influence the development of skin cancer in individuals? select all that apply.

people with light colored skin are more prone to melanoma UV-A is the form of UV radiation most strongly linked with skin cancers

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 -- and frequency.

photons & wavelength

energy is not continuous, but is --, which means that it is divided into "packets" each of which contains a definite amount of energy

quantized

introducing a C=C double bond into the structure of a hydrofluorocarbon --

shortens its atmospheric lifetime reduces its effect on stratospheric ozone reduces its impact on global climate change

what is the term used to describe a condition in which a dynamic system has no net change in concentration of the major species involved?

steady state

UV-C radiation has the highest energy of all the types of radiation but it is not biologically damaging because it never reaches the Earth. UV-C radiation is instead absorbed in the -- by oxygen and --.

stratosphere; ozone

which of the following factors cause an increase in ozone production? select all that apply.

sun closer to the Earth increased intensity of UV radiation sun directly overhead

match each type of uv protection with the correct description sunscreen sunblock

sunscreen-a product that contains chemicals that absorb UV-A and UV-B radiation sunblock-a product that contains compounds like ZnO and TiO2 that physically block UV radiation

which of the following options correctly describes the UV index? select all that apply.

the UV index is based on the length of time required for skin damage to occur A UV index color-coded yellow indicates a moderate level of UV radiation

why is ozone depletion greater over the south pole than the arctic

the air above the north pole is not as cold, so that fewer polar stratospheric clouds form

which of the following statements correctly describe the consequences of halting the production of CFCs? select all that apply.

there has been a slow rate of change in the concentration of stratospheric chlorine since the halt in production of CFCs.

the region of the atmosphere closest to earth is called the --. The region of the atmosphere that contains the ozone layer is called the --.

troposphere; stratosphere

true or false: UV wavelength photons have enough energy to break some chemical bonds

true

match the type of radiant energy with the percentage of total energy emitted by the sun

visible radiation-39% IR radiation- 53% UV radiation- 8%

some UV radiation is beneficial to humans because UV-B light stimulates the production of --, which is important for healthy bones and immune systems.

vitamin D