Photochemical reaction rate does not depend significantly on temperature, because (A) It is a reversible reaction (B) It is an exothermic reaction (C) The energy of reacting molecules exceeds the activation energy by absorption of light (D) None of these

Photochemical reaction rate does not depend significantly on
temperature, because
(A) It is a reversible reaction
(B) It is an exothermic reaction
(C) The energy of reacting molecules exceeds the activation energy by
absorption of light
(D) None of these
by

1 Answer

Answer :

(C) The energy of reacting molecules exceeds the activation energy by
absorption of light
by

Related questions

Pick out the correct statement. (A) Reactions with high activation energies are very temperature sensitive (B) Chemical equilibrium is a static state (C) A photochemical reaction is catalysed by light (D) A chemical reaction occurs when the energy of the reacting molecule is less than the activation energy of the reaction

Description : Pick out the correct statement. (A) Reactions with high activation energies are very temperature sensitive (B) Chemical equilibrium is a static state (C) A photochemical reaction is catalysed by ... occurs when the energy of the reacting molecule is less than the activation energy of the reaction

Last Answer : (A) Reactions with high activation energies are very temperature sensitive (B) Chemical equilibrium is a static state

The increase in the rate of reaction with temperature is due to (A) Increase in the number of effective collisions (B) Decrease in activation energy (C) Increase in the average kinetic energy of the reacting molecules (D) None of these

Description : The increase in the rate of reaction with temperature is due to (A) Increase in the number of effective collisions (B) Decrease in activation energy (C) Increase in the average kinetic energy of the reacting molecules (D) None of these

Last Answer : (B) Decrease in activation energy

A catalyst (A) Initiates a reaction (B) Lowers the activation energy of reacting molecules (C) Is capable of reacting with any one of the reactants (D) Cannot be recovered chemically unchanged at the end of a chemical reaction

Description : A catalyst (A) Initiates a reaction (B) Lowers the activation energy of reacting molecules (C) Is capable of reacting with any one of the reactants (D) Cannot be recovered chemically unchanged at the end of a chemical reaction

Last Answer : (C) Is capable of reacting with any one of the reactants

Pick out the correct statement. (A) In catalytic reactions, the catalyst reacts with the reactants (B) A catalyst initiates a chemical reaction (C) A catalyst lowers the activation energy of the reacting molecules (D) A catalyst cannot be recovered chemically unchanged at the end of the chemical reaction

Description : Pick out the correct statement. (A) In catalytic reactions, the catalyst reacts with the reactants (B) A catalyst initiates a chemical reaction (C) A catalyst lowers the activation energy of ... molecules (D) A catalyst cannot be recovered chemically unchanged at the end of the chemical reaction

Last Answer : (C) A catalyst lowers the activation energy of the reacting molecules

A chemical reaction occurs when the energy of the reacting molecules is __________ the activation energy of the reaction. (A) Less than (B) Equal to (C) More than (D) Equal to or more than

Description : A chemical reaction occurs when the energy of the reacting molecules is __________ the activation energy of the reaction. (A) Less than (B) Equal to (C) More than (D) Equal to or more than

Last Answer : (D) Equal to or more than

A chemical reaction occurs, when the energy of the reacting molecules is __________ the activation energy of reaction. (A) Less than (B) Equal to (C) More than(D) Equal to or more than

Description : A chemical reaction occurs, when the energy of the reacting molecules is __________ the activation energy of reaction. (A) Less than (B) Equal to (C) More than (D) Equal to or more than

Last Answer : (D) Equal to or more than

Pick out the wrong statement. (A) Visible radiation provides the necessary activation energy in photochemical reactions (B) The order and molecularity of a complex reaction may not be the same (C) For a second order reaction, the slope of the graph/plot between rate and (concentration) is equal to the rate constant (k) (D) Molecularity of the reaction is always a whole number greater than zero

Description : Pick out the wrong statement. (A) Visible radiation provides the necessary activation energy in photochemical reactions (B) The order and molecularity of a complex reaction may not be the same (C) For ... rate constant (k) (D) Molecularity of the reaction is always a whole number greater than zero

Last Answer : (B) The order and molecularity of a complex reaction may not be the same

In an exothermic reaction, the energy of the reacting substances as compared to that of products is (A) More (B) Less (C) Same (D) Either (A) or (B), depends on order of reaction

Description : In an exothermic reaction, the energy of the reacting substances as compared to that of products is (A) More (B) Less (C) Same (D) Either (A) or (B), depends on order of reaction

Last Answer : (A) More

A catalyst in a chemical reaction (A) Decreases the activation energy (B) Alters the reaction mechanism (C) Increases the frequency of collisions of reacting species (D) All (A), (B) and (C)

Description : A catalyst in a chemical reaction (A) Decreases the activation energy (B) Alters the reaction mechanism (C) Increases the frequency of collisions of reacting species (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

The reaction rate almost gets doubled for 10°C rise in temperature. This is due to the fact that the (A) Increased temperature reduces the activation energy (B) Fraction of molecules having threshold energy increases (C) Collision frequency increases (D) Value of threshold energy decreases

Description : The reaction rate almost gets doubled for 10°C rise in temperature. This is due to the fact that the (A) Increased temperature reduces the activation energy (B) Fraction of molecules having threshold energy increases (C) Collision frequency increases (D) Value of threshold energy decreases

Last Answer : (B) Fraction of molecules having threshold energy increases

When an exothermic reversible reaction is conducted adiabatically, the rate of reaction (A) Continuously increases (B) Continuously decreases (C) Passes through a maximum (D) Passes through a minimum

Description : When an exothermic reversible reaction is conducted adiabatically, the rate of reaction (A) Continuously increases (B) Continuously decreases (C) Passes through a maximum (D) Passes through a minimum

Last Answer : (C) Passes through a maximum

The reaction between oxygen and organic material is a/an __________ reaction. (A) Exothermic (B) Endothermic (C) Biochemical (D) Photochemical

Description : The reaction between oxygen and organic material is a/an __________ reaction. (A) Exothermic (B) Endothermic (C) Biochemical (D) Photochemical

Last Answer : (A) Exothermic

Conversion increases with increase in temperature in case of a/an__________ reaction.(A) Autocatalytic(B) Irreversible(C) Reversible endothermic(D) Reversible exothermic

Description : Conversion increases with increase in temperature in case of a/an__________ reaction. (A) Autocatalytic (B) Irreversible (C) Reversible endothermic (D) Reversible exothermic

Last Answer : (C) Reversible endothermic

In case of a/an __________ chemical reaction, conversion increases with the rise in temperature. (A) Reversible exothermic (B) Irreversible exothermic (C) Irreversible endothermic (D) Reversible endothermic

Description : In case of a/an __________ chemical reaction, conversion increases with the rise in temperature. (A) Reversible exothermic (B) Irreversible exothermic (C) Irreversible endothermic (D) Reversible endothermic

Last Answer : (D) Reversible endothermic

Fractional conversion __________ for an exothermic reversible chemical reaction, when the temperature is maximum. (A) Increases (B) Remains unchanged (C) Decreases (D) Unpredictable from the data

Description : Fractional conversion __________ for an exothermic reversible chemical reaction, when the temperature is maximum. (A) Increases (B) Remains unchanged (C) Decreases (D) Unpredictable from the data

Last Answer : (C) Decreases

Which of the following is the optimum operating condition for an exothermic reversible reaction taking place in a plug-flow reactor? (A) Temperature should be high in the beginning and decreased towards the end of the reaction (B) Very low temperature should be used throughout the reaction (C) Very high temperature should be used throughout the reaction (D) None of these

Description : Which of the following is the optimum operating condition for an exothermic reversible reaction taking place in a plug-flow reactor? (A) Temperature should be high in the beginning and decreased towards ... reaction (C) Very high temperature should be used throughout the reaction (D) None of these

Last Answer : (A) Temperature should be high in the beginning and decreased towards the end of the reaction

The energy of activation of exothermic reaction is (A) Zero (B) Negative (C) Very large compared to that for endothermic reaction (D) Not possible to predict

Description : The energy of activation of exothermic reaction is (A) Zero (B) Negative (C) Very large compared to that for endothermic reaction (D) Not possible to predict

Last Answer : (D) Not possible to predict

The rate expression for a heterogeneous catalytic reaction is given by, - rA = K.KA PA(1 + KA.PA + KR.PR), where K is surface reaction rate constant and KA and KR are absorption equilibrium constants of A and R respectively. If KR PR >> (1 + KA PA), the apparent activation energy EA is equal to (given E is the activation energy for the reaction and ΔHR and ΔHA are the activation energies of adsorption of R and A) (A) E (B) E + ΔHA (C) E + ΔHA - ΔHR ) (D) ΔHA + ΔHR

Description : The rate expression for a heterogeneous catalytic reaction is given by, - rA = K.KA PA(1 + KA.PA + KR.PR), where K is surface reaction rate constant and KA and KR are absorption equilibrium constants of A and R respectively. If KR PR ... R and A) (A) E (B) E + ΔHA (C) E + ΔHA - ΔHR ) (D) ΔHA + ΔHR

Last Answer : (C) E + ΔHA - ΔHR )

An exothermic reaction is one in which the reacting substances :

Description : An exothermic reaction is one in which the reacting substances :

Last Answer : An exothermic reaction is one in which the reacting substances : A. Have same energy as products ... D. Are at higher temperature than the products

Combustion of a candle is a/an - (1) photochemical reaction (2) physical change (3) endothermic reaction (4) exothermic reaction

Description : Combustion of a candle is a/an - (1) photochemical reaction (2) physical change (3) endothermic reaction (4) exothermic reaction

Last Answer : (4) exothermic reaction Explanation: In theory, a candle is made of a solid hydrocarbon called paraffin. When the solid burns, the hydrocarbon reacts with oxygen to form carbon dioxide and water. The reaction is exothermic, meaning it releases heat to the atmosphere along with the other products.

Combustion of a candle is a/an (1) photochemical reaction (2) physical change (3) endothermic reaction (4) exothermic reaction

Description : Combustion of a candle is a/an (1) photochemical reaction (2) physical change (3) endothermic reaction (4) exothermic reaction

Last Answer : exothermic reaction

Pick out the wrong statement. (A) Use of different catalysts in a reversible catalytic chemical reaction does not change the equilibrium composition (B) Alumina is added as a promoter to iron catalyst in ammonia synthesis reaction (C) Activation energy for a reaction is obtained from the intercept of the Arrhenius plot (D) Presence of inerts affects the equilibrium conversion of reactants in a chemical reaction

Description : Pick out the wrong statement. (A) Use of different catalysts in a reversible catalytic chemical reaction does not change the equilibrium composition (B) Alumina is added as a promoter to ... Arrhenius plot (D) Presence of inerts affects the equilibrium conversion of reactants in a chemical reaction

Last Answer : (C) Activation energy for a reaction is obtained from the intercept of the Arrhenius plot

Pick out the correct statement. (A) A chemical reaction accompanied by absorption of heat is called an exothermic reaction (B) A chemical reaction accompanied by evolution of heat is called an endothermic reaction (C) The rate constant for a first order reaction does not change on changing the concentration units (D) Chemical equilibrium state is dynamic in nature

Description : Pick out the correct statement. (A) A chemical reaction accompanied by absorption of heat is called an exothermic reaction (B) A chemical reaction accompanied by evolution of heat is called an ... does not change on changing the concentration units (D) Chemical equilibrium state is dynamic in nature

Last Answer : (C) The rate constant for a first order reaction does not change on changing the concentration units

The energy of activation of a chemical reaction: (A) Is same as heat of reaction at constant pressure (B) Is the minimum energy which the molecules must have before the reaction can take place (C) Varies as fifth power of the temperature (D) Both (B) and (C)

Description : The energy of activation of a chemical reaction: (A) Is same as heat of reaction at constant pressure (B) Is the minimum energy which the molecules must have before the reaction can take place (C) Varies as fifth power of the temperature (D) Both (B) and (C)

Last Answer : (B) Is the minimum energy which the molecules must have before the reaction can take place

Reactions with high activation energy are (A) Very temperature sensitive (B) Temperature insensitive (C) Always irreversible (D) Always reversible

Description : Reactions with high activation energy are (A) Very temperature sensitive (B) Temperature insensitive (C) Always irreversible (D) Always reversible

Last Answer : (A) Very temperature sensitive

Formation of ammonium carbamate by reaction of NH3 with CO2 is a/an __________ reaction. (A) Catalytic (B) Exothermic (C) Endothermic (D) Reversible

Description : Formation of ammonium carbamate by reaction of NH3 with CO2 is a/an __________ reaction. (A) Catalytic (B) Exothermic (C) Endothermic (D) Reversible

Last Answer : (B) Exothermic

Dehydration of ammonium carbamate (to produce urea) is a/an __________ reaction. (A) Reversible (B) Catalytic(C) Exothermic(D) Endothermic

Description : Dehydration of ammonium carbamate (to produce urea) is a/an __________ reaction. (A) Reversible (B) Catalytic (C) Exothermic (D) Endothermic

Last Answer : (D) Endothermic

In the reversible reaction of the type, A + B ⇌ AB, in general (A) Both forward and backward reactions will be exothermic (B) Neither of the reactions will be endothermic (C) The combination reaction will be exothermic, while the dissociation reaction will be endothermic (D) The combination reaction will be endothermic, while the dissociation reaction will be exothermic

Description : In the reversible reaction of the type, A + B ⇌ AB, in general (A) Both forward and backward reactions will be exothermic (B) Neither of the reactions will be endothermic (C) ... will be endothermic (D) The combination reaction will be endothermic, while the dissociation reaction will be exothermic

Last Answer : (C) The combination reaction will be exothermic, while the dissociation reaction will be endothermic

A typical example of an exothermic reversible reaction conducted at high pressure in industry is (A) Dehydration of ethanol (B) Methanol synthesis (C) Reformation of methane (D) Polymerisation of ethylene

Description : A typical example of an exothermic reversible reaction conducted at high pressure in industry is (A) Dehydration of ethanol (B) Methanol synthesis (C) Reformation of methane (D) Polymerisation of ethylene

Last Answer : (A) Dehydration of ethanol

For the reversible exothermic reaction, N2 + 3H2 ⇌ 2NH3, increase of pressure would (A) Shift the equilibrium towards right (B) Give higher yield of NH3 (C) Both (B) and (C) (D) Neither (A) nor (B)

Description : For the reversible exothermic reaction, N2 + 3H2 ⇌ 2NH3, increase of pressure would (A) Shift the equilibrium towards right (B) Give higher yield of NH3 (C) Both (B) and (C) (D) Neither (A) nor (B)

Last Answer : (C) Both (B) and (C)

The difference between Threshold energy and average energy of the molecules is called activation energy. Ina chemical reaction lowers the rate of reaction the greater will be. The activation energy

Description : The difference between Threshold energy and average energy of the molecules is called activation energy. Ina chemical reaction lowers the rate of reaction the greater will be. The activation energy

Last Answer : How do you define the molecularity of a reaction ?

Pick out the correct statement. (A) Higher hold up of the solid in the rotary dryer results in better exposure of the solids to the gas (B) The 'Hatta number' is important in problems involving gas absorption without chemical reaction (C) For a non-reacting binary mixture of ideal gases, the partial pressure distribution of both components is linear in the case of steady state equimolal counter-diffusion (D) Total reflux in case of distillation operation requires infinite number of plates for a binary system separation

Description : Pick out the correct statement. (A) Higher hold up of the solid in the rotary dryer results in better exposure of the solids to the gas (B) The 'Hatta number' is ... reflux in case of distillation operation requires infinite number of plates for a binary system separation

Last Answer : (C) For a non-reacting binary mixture of ideal gases, the partial pressure distribution of both components is linear in the case of steady state equimolal counter-diffusion

Pick out the wrong statement (A) Co-current absorbers are usually used, when the gas to be dissolved in the liquid is a pure substance (B) In case of gas absorption, HETP is equal to HTU, when both the operating line & the equilibrium lines are parallel (C) Hatta number is important in case of gas absorption with chemical reaction (D) In actual practice, absorption is an endothermic process, while stripping is an exothermic process

Description : Pick out the wrong statement (A) Co-current absorbers are usually used, when the gas to be dissolved in the liquid is a pure substance (B) In case of gas absorption, HETP is ... reaction (D) In actual practice, absorption is an endothermic process, while stripping is an exothermic process

Last Answer : (D) In actual practice, absorption is an endothermic process, while stripping is an exothermic process

The rate of reaction of a/an __________ reaction is not affected by temperature rise. (A) Autocatalytic (B) Photochemical (C) Consecutive (D) Zero order

Description : The rate of reaction of a/an __________ reaction is not affected by temperature rise. (A) Autocatalytic (B) Photochemical (C) Consecutive (D) Zero order

Last Answer : (B) Photochemical

Pick out the correct statement. (A) A lower temperature favours the reaction of lower activation energy (B) The dispersion number for a reactor/vessel is uL/D (C) The rate controlling step in a reaction involving many steps is the fastest step (D) Pore volume and porosity of a catalyst is measured by Brunauer￾Emmett-Teller (BET) technique

Description : Pick out the correct statement. (A) A lower temperature favours the reaction of lower activation energy (B) The dispersion number for a reactor/vessel is uL/D (C) The rate controlling step in ... step (D) Pore volume and porosity of a catalyst is measured by Brunauer￾Emmett-Teller (BET) technique

Last Answer : (A) A lower temperature favours the reaction of lower activation energy

Pick out the wrong statement. (A) In a multistep reaction, the slowest step is the rate determining step (B) In general, the rate of a reaction becomes triple for every 10°C rise in temperature (C) Slow chemical reactions have generally high values of activation energy (D) Molecularity of a reaction cannot be zero but the order of a reaction can be zero

Description : Pick out the wrong statement. (A) In a multistep reaction, the slowest step is the rate determining step (B) In general, the rate of a reaction becomes triple for every 10°C rise in temperature (C ... energy (D) Molecularity of a reaction cannot be zero but the order of a reaction can be zero

Last Answer : (B) In general, the rate of a reaction becomes triple for every 10°C rise in temperature

Higher free energy of activation of a chemical reaction (at a given temperature) implies (A) Slower rate of reaction (B) Higher rate of reaction (C) Higher equilibrium conversion (D) Both (B) and (C)

Description : Higher free energy of activation of a chemical reaction (at a given temperature) implies (A) Slower rate of reaction (B) Higher rate of reaction (C) Higher equilibrium conversion (D) Both (B) and (C)

Last Answer : (A) Slower rate of reaction

If the rate of a chemical reaction becomes slower at a given temperature, then the (A) Initial concentration of the reactants remains constant (B) Free energy of activation is lower(C) Entropy changes(D) Free energy of activation is higher

Description : If the rate of a chemical reaction becomes slower at a given temperature, then the (A) Initial concentration of the reactants remains constant (B) Free energy of activation is lower (C) Entropy changes (D) Free energy of activation is higher

Last Answer : (D) Free energy of activation is higher

Arrhenius equation represents graphically the variation between the __________ and temperature. (A) Rate of reaction (B) Frequency factor (C) Rate constant (D) Activation energy

Description : Arrhenius equation represents graphically the variation between the __________ and temperature. (A) Rate of reaction (B) Frequency factor (C) Rate constant (D) Activation energy

Last Answer : (C) Rate constant

Arrhenius equation shows the variation of __________ with temperature. (A) Reaction rate (B) Rate constant (C) Energy of activation (D) Frequency factor

Description : Arrhenius equation shows the variation of __________ with temperature. (A) Reaction rate (B) Rate constant (C) Energy of activation (D) Frequency factor

Last Answer : (B) Rate constant

A photochemical reaction is __________ light. (A) Initiated by (B) Accompanied with emission of (C) Catalysed by (D) Used to convert heat energy into

Description : A photochemical reaction is __________ light. (A) Initiated by (B) Accompanied with emission of (C) Catalysed by (D) Used to convert heat energy into

Last Answer : (A) Initiated by

Fibrinolytic therapy is based on activation of plasminogen, the inactive proteolytic enzyme of plasma that binds to fibrin during the formation of thrombosis. Activation of plasminogen to plasmin results in selective thrombolysis at the fibrin clot surface. Which of the following statement(s) is/are true concerning agents used in thrombolytic therapy? a. Streptokinase is a bacterial protein which is antigenic in humans, resulting in allergic reactions in up to l5% of cases b. Tissue plasminogen activator acts directly on plasmin without an intermediate drug–plasmin complex c. The half-life of urokinase, streptokinase, and TPA all exceed 30 minutes d. Streptokinase is significantly cheaper than urokinase or TPA

Description : Fibrinolytic therapy is based on activation of plasminogen, the inactive proteolytic enzyme of plasma that binds to fibrin during the formation of thrombosis. Activation of plasminogen to plasmin results ... TPA all exceed 30 minutes d. Streptokinase is significantly cheaper than urokinase or TPA

Last Answer : Answer: a, b, d Streptokinase is a bacterial protein produced by group C b-hemolytic streptococci. It is therefore antigenic in humans and can be associated with allergic reaction in ... one agent over the other. Streptokinase however, is markedly less expensive than either urokinase or TPA

Assertion(A): Physical adsorption of molecules on the surface requires activation energy. Reason(R): Because the bonds of adsorbed molecules are broke

Description : Assertion(A): Physical adsorption of molecules on the surface requires activation energy. Reason(R): Because the bonds of adsorbed molecules are broke

Last Answer : Assertion(A): Physical adsorption of molecules on the surface requires activation energy. Reason(R): ... D. If both Assertion & Reason are False.

The atmosphere near the earth’s surface is “heated from below.” Which of the following does not significantly contribute to this heating -----------? A. Conduction of heat upward from a hot surface B. Convection from a hot surface C. Absorption of infrared energy that has been radiated from the surface D. Heat energy from the earth’s interior (Answer)

Description : The atmosphere near the earth's surface is heated from below. Which of the following does not significantly contribute to this heating -----------? A. Conduction of heat upward from a ... infrared energy that has been radiated from the surface D. Heat energy from the earth's interior (Answer)

Last Answer : D. Heat energy from the earth’s interior (Answer)

An increase in which of the following results in a decrease in the rate of the chemical reaction? (a) temperature (b) concentration (c) collision frequency (d) energy of activation

Description : An increase in which of the following results in a decrease in the rate of the chemical reaction? (a) temperature (b) concentration (c) collision frequency (d) energy of activation

Last Answer : energy of activation

In an exothermic chemical reaction, the reactants compared to the products have (A) Higher temperature (B) More energy (C) Less energy (D) Same energy

Description : In an exothermic chemical reaction, the reactants compared to the products have (A) Higher temperature (B) More energy (C) Less energy (D) Same energy

Last Answer : (B) More energy

A second order liquid phase reaction, A → B, is carried out in a mixed flow reactor operated in semi batch mode (no exit stream). The reactant A at concentration CAF is fed to the reactor at a volumetric flow rate of F. The volume of the reacting mixture is V and the density of the liquid mixture is constant. The mass balance for A is (A) d(VCA )/dt = -F (CAF - CA ) - kCA 2V (B) d(VCA )/dt = F (CAF - CA ) - kCA 2V (C) d(VCA )/dt = -FCA - kCA 2V (D) d(VCA )/dt = FCAF - kCA 2V

Description : A second order liquid phase reaction, A → B, is carried out in a mixed flow reactor operated in semi batch mode (no exit stream). The reactant A at concentration CAF is fed to the reactor at a volumetric flow rate of F. The volume ... 2V (C) d(VCA )/dt = -FCA - kCA 2V (D) d(VCA )/dt = FCAF - kCA 2V

Last Answer : (D) d(VCA )/dt = FCAF - kCA 2V

"The rate at which a substance reacts is proportional to its active mass and the rate of a chemical reaction is proportional to the product of active masses of the reacting substances". This is the (A) Lewis-Randall rule (B) Statement of Van't Hoff Equation (C) Le-Chatelier's principle (D) None of these

Description : "The rate at which a substance reacts is proportional to its active mass and the rate of a chemical reaction is proportional to the product of active masses of the reacting substances". This is the (A) Lewis- ... (B) Statement of Van't Hoff Equation (C) Le-Chatelier's principle (D) None of these

Last Answer : (D) None of these

Molecular diffusion is caused by the (A) Transfer of molecules from low concentration to high concentration region (B) Thermal energy of the molecules (C) Activation energy of the molecules (D) Potential energy of the molecules

Description : Molecular diffusion is caused by the (A) Transfer of molecules from low concentration to high concentration region (B) Thermal energy of the molecules (C) Activation energy of the molecules (D) Potential energy of the molecules

Last Answer : (B) Thermal energy of the molecules

A photochemical reaction is(A) Accompanied with emission of light (B) Catalysed by light (C) Initiated by light (D) All (A), (B) & (C)

Description : A photochemical reaction is (A) Accompanied with emission of light (B) Catalysed by light (C) Initiated by light (D) All (A), (B) & (C)

Last Answer : (C) Initiated by light