14 Copper(II) oxide reacts with hydrogen.
CuO + H2 → Cu + H2O
Which row is correct?
oxidising agent
reducing agent
A
H2
Cuo
B
Cuo
H2
с
H2O
Cu
D
Cu
H20

Answers

Answer 1

Answer:

B

CuO

H2

Explanation:

hydrogen will oxidized to form water

Answer 2

Copper(II) oxide reacts with hydrogen.

[tex]CuO + H_2[/tex] → [tex]Cu + H_2O[/tex]

Oxidising agent - [tex]Cuo[/tex]

Reducing agent - [tex]H_2[/tex]

What is a redox reaction?

A chemical reaction that takes place between an oxidizing substance and a reducing substance.

The oxidizing substance loses electrons in the reaction, and the reducing substance gains electrons.

In the reaction  [tex]CuO + H_2[/tex] → [tex]Cu + H_2O[/tex]  

[tex]Cuo[/tex] is the oxidising agent and  [tex]H_2[/tex] is the reducing agent because [tex]Cuo[/tex]  is oxidising  [tex]H_2[/tex] and [tex]H_2[/tex] is the reducing agent because it is removing oxygen from [tex]Cuo[/tex].

Hence, option B is correct.

Learn more about the redox reaction here:

https://brainly.com/question/13293425

#SPJ2


Related Questions

PLEASE HELP RIGHT AWAY!! THANK YOU :)
Copper turns a green-brown when it is exposed to oxygen in air. What chemical property of oxygen causes this effect?

A). its reactivity

B). its mass

C). its flammability

D). its volume

Answers

Answer:

The answer is option A.

its reactivity

I hope this helps you.

Answer:

A) Reactivity

Explanation:

Reactivity is one of the characteristics of a chemical property. The copper that turned color due to air, has a different chemical composition.

It wouldn't be flammability - even though it is a chemical property, but nothing is burning.

All the other answer choises: mass and volume are physical properties. Basically the PHYSICAL characteristics which doesn't change the composition.

Hope this helps!

Which process is a chemical change? burning a match boiling water melting ice breaking glass

Answers

Answer:

Burning a match

Explanation:

A chemical change is where a substance is changed into one or more substances. Basically, a chemical change changes the form of a substance. While, a physical change such as ripping a piece of paper in half will still be a paper just in half(nothing is changed).

Hope this helps!!! PLZ MARK BRAINLIEST!!!

Combustion is a chemical reaction that often involves the presence of oxygen and produces heat and light in the form of flames. Burning a match is a chemical change. Therefore, option A is correct.

What is combustion ?

A fuel and an oxidant, typically atmospheric oxygen, engage in a high-temperature exothermic redox chemical reaction known as combustion, or burning, which results in the production of oxidized, frequently gaseous products in a mixture known as smoke.

Burning is sometimes referred to as combustion. Fuel is burned and interacts with oxygen in a combustion reaction to produce energy.

A fuel and an oxidant, often atmospheric oxygen, engage in a high-temperature exothermic (heat-releasing) redox (oxygen-adding) chemical reaction during combustion that results in oxidized, frequently gaseous products in a mixture known as smoke.

Thus, option A is correct.

To learn more about combustion, follow the link;

https://brainly.com/question/15117038

#SPJ6

HELP PLEASEE 100 POINTS
The Quiver tree grows in Southern Africa. Which of the following plant adaptations is likely to prevent these trees from dying out due to rising desert temperatures?
O Releasing a black powder onto their trunk to absorb more heat from sunlight
O Shifting their growing range towards the equator
Ability to store water in leafy structures to prevent excess evaporation
O Limiting seed dispersal to nearby locations
PLEASE HELP 100 POINTS !!

Answers

Answer:

Shifting their growing range towards the equator

Explanation:

Maybe will be like that

Answer:

Ability to store water in leafy structures to prevent excess evaporation.

Explanation:

The reason why plants die in hot temperature is the excess evaporation of water, so to prevent the excess evaporation of water, the plants get adaptive to store water in their leaves.

Hope it helps.

In which situation would hydrogen bonding be present?
A. When hydrogen exists as an ion in solution
B. When hydrogen is attached to C, S, or P
C. When hydrogen is attached to N, F or o
D. When hydrogen atoms bond together to form H2

Answers

Answer:

C

Explanation:

hydrogen Bond exists between ammonia, hydrogen flouride and water so the answer is C

Identify the missing numbers below to show the result of dividing the numbers 5.6 x 10^12 / 3.5 x 10^9 = A x 10^B

Answers

Answer:

A = 1.6

B = 3

Explanation:

When you are dividing exponents, you subtract them:

10^12 / 10^9 = 12 - 9 = 3

10³ would be the exponent

5.6/3.5 = 1.6

So, 1.6(10³) would be your answer.

How many grams of AuCl2, if the compound has 6.3 x10^23 atoms of Cl?

Answers

Answer:

Total mass =  93.21 gram (Approx)

Step-by-step explanation:

Given:

Atoms of Cl = 6.3 × 10²³

Find:

Amount of AuCl₂

Computation:

Molecules of AuCl₂ = 6.3 × 10²³ / 2 = 3.15 × 10²³

1 mol of AuCl₂ = 6.022 × 10²³ molecules

Number of mol = 3.15 × 10²³ /  6.022 × 10²³

Number of mol  = 0.523 mol

So,

Molar mass of AuCl₂ = 267.87 g/mol

Total mass = 0.348 mol × 267.87 g/mol

Total mass =  93.21 gram (Approx)

What are some indicators of rusting? Check all that apply. production of light color change formation of a solid formation of a gas

Answers

Answer:

Some indicators of rusting include:

a. color change

b. formation of as solid

Explanation:

Rusting is a redox ( a reaction in which reduction and oxidation occur concurrently) reaction which occcur when metallic iron is exposed to air and water or water vapor reacts with the oxygen and water to form a hydrated mixture of oxides of the metal.

The shiny metallic iron becomes oxidized to Fe²⁺ and Fe³⁺ ions while neutral oxygen gas molecules are reduced to O²⁻ ions. The shiny metallic iron also loses its lustrous appearance as the process proceeds and is covered by a layer of rust.

The equation for reaction is given below:

4Fe(s) + 30₂(g) + xH₂O(l) -----> 2Fe₂O₃. xH₂O(s)

The product of the reaction above is known as rust and is reddish-brown solid.

Rusting causes iron to become flaky and weak as rust is very light and porous, reducing the strength and appearance of iron which are desirable properties of iron when used in construction. The rusting of iron can lead to damage to automobiles, railings, bridges, and several other iron structures.

Answer:

color change and formation of a solid.

Explanation:

the answer that comes after is chemical also hope this helps!

1. Which of these items wastes sound energy?
-car radio
-alarm clock
-washing machine
-smartphone

Answers

Answer:

washing machine

Explanation:

the sound from a washing machine is not beneficial in any way

What is cationic and anionic polymers?

Answers

Answer:

Explanation:

Anionic polymerization and cationic polymerization are two types of chain growth polymerization reactions which are used to synthesize various types of polymers. Both these reactions have the same reaction mechanism, but the reaction initiator is different. Anionic polymerization reactions are initiated by an active anionic species, whereas the cationic polymerization reactions are initiated by an active cationic species.

hope this helps

plz mark it as brainliest\

A metal strip reacts slowly when placed in a light blue solution, and much faster when placed in a dark blue solution at the same temperature. Using the collision theory, explain this phenomenon.

Answers

Answer:

Increase in the color intensity and hence the concentration of the reacting species increases the rate of the reaction according to collision theory

Explanation:

The given parameters are;

Rate of reaction of metal strip in light blue solution lesser than rate  of reaction of the metal strip in dark blue solution

Therefore, the color of the solution derives from the concentration of the reacting species involved in the reaction.

The increase in the darkness of the blue solution stems from the increase in the concentration of the reacting species which according to collision theory increases the fraction of the effective collisions, thereby increasing the reaction rate.

y
Why is helium
monoatomic in nature?​

Answers

Answer:

Nitrogen stands out because its atoms share a strong triple bond, making it a very stable substance. The noble gases, such as helium and neon, rarely form molecules at all; they are monatomic.

Explanation:

Answer:

Noble gases are monoatomic because they have complete octet (apart from Helium, which has duet) , hence they are highly stable on their own and do not react with others to form compounds in standard temperature and pressure conditions. ... All the electron shells in the noble gasses are full of electrons.

What would be the mass of Iron(II) chloride obtained when 450g of Sodium Chloride is added to Iron(II) oxide?

Answers

Answer:

FeO(s)+2NaCL(aq)>FeCL2(aq)+Na2O(s)

2 moles of sodium chloride react with 1 mole of iron (II) oxide to give 1 mole of iron (II) chlorine

mole ratio NaCl :FeCl=2:1

mass of FeCl=0.5×450=225g

Explanation:

(

Lactose (milk sugar) is a carbohydrate that is formed by combining galactose and glucose. Which term best describes this molecule? monosaccharide disaccharide monomer starch

Answers

Explanation:

lactose is disaccharide

because it contains 1 monosaccharide galactose +

1 monosaccharide glucose

The correct answer to the question is: disaccharide

Monosaccharides are simple sugar which can not be hydrolysed into simpler or smaller molecules.

Disaccharides are sugars produced by the condensation of two monosaccharides with the elimination of a water molecule.

monosaccharide + monosaccharide <=> Disaccharide + water

A Monomer is a small molecule which can combine with other similar molecules to form a large molecule called polymer. Thus, a monomer of starch is simply a small molecule that combines together to form a polysaccharide called starch. The monomer of starch is glucose.

Glucose and galactose combined to form lactose i.e

Glucose + Galactose => Lactose

The above is simply a demonstration of how disaccharides are produced.

Learn more: https://brainly.com/question/20336107

What type of compound are carbon tetrachloride and boron trihydride?

Answers

Answer:

hydrocarbon

Explanation:

these are called hydrocarbons

how many atoms altogether make up one molecule of glucose ​

Answers

Answer:

24 atoms makes altogether a molecule of glucose

What was the plum-pudding atomic model? A. A description of atoms being balls of positive charge with electrons scattered outside B. A description of electrons orbiting the nucleus of the atom C. A description of electrons scattered inside the atom D. A description of negative charges being suspended between balls of positive charge

Answers

Answer:

C

Explanation:

plum- pudding atomic model is an atom that had a positively charged medium, or space, with negatively charged electrons inside the medium.

The correct answer is (A) A description of atoms being balls of positive charge with electrons scattered outside.

What is plum pudding atomic model? The plum pudding atomic model was proposed by JJ Thomson.This atomic model had electrons embedded with positive charge.The plums were negatively charged electrons the pudding were the positively-charged protons.

Why other options are incorrect?

Option (A) is correct because the atom was a sphere of positive charge with negatively charged electrons scattered around the atom like plums in a pudding.

So , Rest  options that are B , C and D are incorrect.

Learn more about Plum pudding model below

https://brainly.com/question/15126038

#SPJ2

What can you infer about the results of numerical models in 1966 for polar caps
made of water ice?

Answers

Answer:

that by living near the poles, people might be able to survive on Mars

Explanation:

The production of water proceeds according to the following equation.
2H2(g) + O2(g) → 2H2O(g)
Which describes a way to speed up the collisions between hydrogen and oxygen molecule:
Use a less-intense source of heat on the reactants.
Maintain the same temperature of the reactants.
Place the reactants in a smaller container.
Reduce the concentration of the reactants.

Answers

Answer:

Place the reactants in a smaller container.

Explanation:

If you were to reduce the source of heat, the hydrogen and oxygen molecules would lose their kinetic energy, resulting in less collisions.

_______________________________________________________

Maintaining the same temperature of the reactants, the speed would neither increase nor decrease as temperature is directly proportional to the kinetic energy of the molecules, which in turn is directly proportional to the number of collisions. However, placing the reactants in a smaller container would result in less volume, and hence the molecules would collide with one another more often!

Hope that helps!

The primary requirement of a reaction to occur is that the reactant particles must collide and interact with each other in some way. Place the reactants in a smaller container which speed up the collisions between hydrogen and oxygen molecule. The correct option is C.

What is collision theory?

The collision theory states that the rate of a chemical reaction is proportional to the number of collisions between the reactant molecules. The more often reactant molecules collide, the more often they react with one another and faster will be the reaction rate.

If we reduce the source of heat, the hydrogen and oxygen molecules would lose their kinetic energy, resulting in less collisions. The temperature is directly proportional to the kinetic energy of the molecules, which in turn is directly proportional to the number of collisions.

If we place the reactants in a smaller container it would result in less volume, and hence the molecules would collide with one another more often.

Thus the correct option is C.

To know more about collision, visit;

https://brainly.com/question/24616147

#SPJ7

why aqueous solution of ethanol does not conduct electricity while an aquoes solution of ethanoic acid conducts electricity

Answers

Answer:

Explanation:

because ethanoic acid dissocaites into H+ and actetate ion so there is positive and negative chaeges to carry the electrons while ethanol only got evenly distributed in the water.

General Lab Questions: (8 points) 5. A) What is the main problem with precipitating strontium ions from the town's water using phosphate? Can you think of any reasons that your results might not be accurate?

Answers

Answer:

1) high pH is required

2) other ions are precipitated along with the strontium ions

Explanation:

According to the solubility rules all phosphates are insoluble except those of sodium, potassium, and ammonium. This implies that strontium phosphate is insoluble in water. This explains why strontium ions can be precipitated from drinking water supply using phosphate. The main problem with the precipitation of strontium using phosphate is that it usually requires a high pH as the precipitation occurs under very alkaline conditions.

The main reason why the results may not be accurate is that other ions are precipitated along with the strontium such as calcium ions and magnesium ions. This may lead to inaccurate determination of the amount of strontium ions present.

Answer:

Explanation:

The fundamental issue for precipitation of Strontium Phosphate, is that the other metal cations (Calcium, Barium, Iron, and so on.), present in the town water, are likewise encouraged as Phosphate. In this manner, alongside Strontium Phosphate, Phosphates of a few different cations are additionally encouraged. In this way, Strontium Phosphate can't be weighed precisely. This will prompt off base outcomes.  

The response will be Exothermic, if the temperature of response increments.

an element x atomic number 16 reacts with an element Y atomic number 20 to form a compound
i) position of the elements in the modern periodic table
ii) what type of bond will be formed between them ? give reason
iii) write the chemical formula of the compound ​

Answers

Answer:

Element x has an atomic number of 16, it is sulphur.

Element Y has an atomic number of 20, it is calcium.

i) Sulphur is in Group VI, period 3 in the modern periodic table,

whereas calcium is in Group II, period 4 of the modern periodic table.

ii) Ionic bonds will form between them. This is because metals and non-metals (Cacium and sulphur) usually form ionic compounds where between the ions are held by ionic bonds (which are transferred electrons so that both elements can attain a stable status).

iii) CaS

each Calcium atom can lose 2 electrons to attain 8 outermost shell electrons, while each sulphur atom can gain the 2 electrons to attain 8 outermost shell electrons, where they will most be stable (octet). Hence, the atomic ratio of Ca and S is 1:1.

i) The element with atomic number 16 is sulfur present in group 16 and period 3rd and the element with atomic number 20 is calcium present in group 2 and period 4th.

ii) The ionic bond formed between them.

ii) The chemical formula of the compound will be CaS.

What are ionic compounds?

Ionic compounds can be described as crystalline solids formed by closely packed ions of opposite charge. An Ionic compound is generally formed when metal reacts with non-metal.

In ionic compounds, the ions are commonly held together by ionic bonds. The ions are formed by gaining or losing electrons in order to achieve their nearest noble gas configuration.

In a reaction, the metals usually lose electrons to complete their octet while non-metals will gain electrons to complete their octet.

The given element calcium is a metal with a valency of +2 and sulfur is a non metal with a valency of -2. Therefore, they form an ionic compound with the chemical formula CaS.

Learn more about ionic compounds, here:

https://brainly.com/question/17217225

#SPJ2

HURRY I'M ON A TIMER

A stovetop bumer on medium reaches 95°C. Which other object will receive a flow of heat directly from the burner?
the surrounding air
a burner at the same temperature
a pan heated to 100°C
hotter water inside a pan​

Answers

Answer:the surrounding air

Explanation:

A burner at the sanem temperature would not receive a flow of heat, a pan heated to 100 degrees will transfer heat to the stovetop, and hotter water inside a pan will not take the heat either because it is hotter. the surrounding air is colder and will take heat from the burner

Answer:

surrounding air

Explanation:

taking test too

What type of organism secretes calcium carbonate plates that overlap to form a spherical test?
A. Coccolithophores
B. Decomposers
C. Dinoflagellates
D. Diatoms

Answers

Answer:

A. Coccolithophores

Explanation:

Coccolithophores are organisms that are single-celled, and secret calcium carbonate plates. They produce calcium carbonate plates that is referred to as coccoliths.

These organisms absorb carbon dioxide during the production of their food. After its death, the calcium carbonate can be collected from the remains. Therefore causing an increase generally in the carbon deposits.

Answer:

A. Coccolithophores

Explanation:

Coccolithophores Create a calcium carbonate plating that protects the cell's surface. This action is called spherical coating.

is it true to say that exhaled air is acidic and why

Answers

Answer:

"True"

Explanation:

Breathing released by humans is naturally acidic. When humans inhale, there are also dangerous toxic substances such as carbon dioxide in the lungs inside the human body, which are neutralized with the help of HCl hydrochloric acid, but due to hydrochloric acid, the breath that man leaves becomes acidic.

Production of synthetic fibers helps in the conservation of forests comment

Answers

Answer:

Explanation:

Synthetic fibres are made using chemicals. Hence they do not require any forest resources like wood. This helps in saving the trees from cutting down. So the production of synthetic fibers helps in the conservation of forests.

Natural fibres on the other hand require forest products like wood for its manufacture.

Hope this helps

plz mark it as brainliest!!!!!!!!!

Answer:

yes, they do help in conservating the forest resources.

Explanation: This is because synthetic fibers like rayon, nylon etc are made from petrochemicals which helps to substitute usage of natural resources like cotton etc. and these synthetic fibers are more durable than natural fibers, which adds to their usage and in turn, helps to conserve forest resources.

why does bromine not react with sulphur?​

Answers

Answer:

The thermodynamic parameter which is of significance in this case is the 'Reduction Potential' for molecular bromine which is ~ +1.1 v vs N.H.E. In other words, it is a strong oxidizing agent. The bromine will oxidize sulfur compounds in which the valence of sulfur is lower than six to sulfate.

There are many possible reactions. Here is one possible example:

Na2 S2O3 + 4Br2 + 5 H2O = 2NaHSO4 + 8 HBr

Answer:

because bromine doesn't have a reaction channel on Yootube.

Explanation:

Speaks for itself.

Determine the density of a substance that weighs 640 grams and occupies a volume of 1 cube it has 4 cm edge

Answers

Explanation:

Density = mass / volume

ρ = 640 g / (4 cm)³

ρ = 10 g/cm³

Name each of the following binary compounds or ionic compounds with polyatomic ions: 1. LiBr 2. Cal2 3. Al203 4. Mg3N2 5. FeCl2 6. FeCl3 7. Cu3N2 8. Ni2O3 9. Al(SO4)3 10. Ca3(PO4)2 11. Fe(OH)2 12. (NH4)2S 13. Na2O 14. NH3 15. SO42-

Answers

Answer:

Explanation:

1. LiBr   -      Lithium bromide

2. Cal₂   - Calcium iodide

3. Al₂0₃  - Aluminium oxide

4. Mg₃N₂  - Magnesium nitride

5. FeCl₂   Ferrous chloride [ Iron(II) chloride ]

6. FeCl₃   Ferric chloride   [ Iron(III) chloride ]

7. Cu₃N₂  Copper nitride

8. Ni₂O₃  Nickel(III) oxide

9. Al(SO4)₃ Aluminium sulphate

10. Ca₃(PO4)₂ Copper phosphate

11. Fe(OH)₂ Iron (II)  hydroxide

12. (NH4)₂S Ammonium sulphide

13. Na₂O   Sodium oxide

14. NH₃     Ammonia

15. SO₄²⁻  Sulphate ion

Which commercial technology commonly uses plasmas?
O a radio
O a race car
O a television a microwave oven

Answers

a television uses plasmas

The commercial technology that uses plasmas is C. A television.

What is plasma ?

Plasma is a state of matter that is similar to gas, but the atoms are ionized, meaning that they have lost or gained electrons. Plasmas are used in a variety of commercial technologies, including:

Plasma TVs use plasma to create images. The plasma is contained in a thin layer of gas between two glass plates. When an electric field is applied to the plasma, it emits light. The color of the light depends on the type of gas used.

Plasma lamps are used in a variety of lighting applications, including streetlights, headlights, and backlighting for LCD displays.

Find out more on plasmas at https://brainly.com/question/18207038

#SPJ6

A group of students conducts an experiment to test the amount of sugar that can be dissolved in water at 50°F, 100°F, and 200°F.

Which suggestion will help increase confidence in the result?

A. Michael suggests timing each addition of sugar
B. Ali suggests using her hand to verify the temperature of the water
C. Joel suggests testing salt along with sugar to see if they dissolve at different speeds
D. Zander suggests that each student complete an experiment individually and compare results​

Answers

Answer:

A. Michael suggests timing each addition of sugar

Explanation:

The experiment is about amount of sugar dissolved at different temperatures. The suggestion of Michael is best suited to record the timing of each addition of sugar. This will enable to record the timing of sugar added in the water and amount of sugar dissolved at the specified temperature.

Other Questions
What are the types of country according to development ratio? A sales team estimates that the number of new phones will sell is a function of the price that it sets. It estimates that if it sets the price at x dollars, it will sell f(x)=3,776-4x phones. Therefore, the company's revenues is x*(3776-4x). What did the popular movies of the Depression reveal about American values at that time? How did these values contrast with the values Americans held before the Depression? rawford Trucking plans to dispose of two trucks in 2022. They sell the first truck on January 2 and the second truck on July 9. If the end of their fiscal year is December 31, how will the calculation of book value differ for these two vehicles? A retail store sells two types of shoes, sneakers and sandals. The store owner pays $8 for the sneakers and $14 for the sandals. The sneakers can be sold for $10 and the sandals can be sold for $17. The owner of the store estimates that she won't sell more than 200 shoes each month, and doesn't plan to invest more that $2,000 on inventory of the shoes. Let x= the number of sneakers in stock, and y=the number of sandals in stock. Write an equation to show the profit she will make on sneakers and sandals. P = [answer0] Plz help ASAP I WILL GIVE BRAINLIEST!! Emily was going to sell all of her stamp collection to buy a video game. After selling half of them she changed her mind. She then bought seventeen more.IF SHE STARTED WITH 46 STAMPS, how many does she have now? A. 75 B. 40 C. 29 D. 63 Which is an example of a gothic character?A. A madmanB. A psychologist C. A bankerD. A doctor Vicki and Tamra are working on their math homework together. Vicki has worked p problems, and Tamra has worked 4 times as many problems as Vicki. The expression shows how many problems they have worked altogether. p + 4p Which of the following is another expression that could be used to get the same result, and what does it represent? A. 5p2. This represents that Vicky and Tamra have worked on 5p2 problems altogether. B. p + 4. This represents that Vicky and Tamra have worked on p + 4 problems altogether. C. 5p. This represents that Vicky and Tamra have worked on 5p problems altogether. D. p + 5. This represents that Vicky and Tamra have worked on p + 5 problems altogether. Setting is the time and placeof a story. Underline thewords in lines 5-6 that showwhere this part of the storytakes place. When do youthink this story takes place? What is one problem still facing women in the United States today? Decide if Y=3x-9 and Y=4x-9 have many solutions, one solution, or no solutions. What are 3 Divine Characteristics shown in Jesus Baptism? Explain? Mary wants to paint her bedroom. Each wall takes 1/3 of a liter of paint. If she buys 2 liters ? pointof paint, how many walls can she paint? * a playground merry-go-round of radius r = 2.20 m has a moment of inertia i = 245 kg m2 and is rotating at 11.0 rev/min about a frictionless vertical axle. facing the axle, a 26.0-kg child hops onto the merry-go-round and manages to sit down on the edge. what is the new angular speed of the merry-go-round? Gabe can wrap 1 2/3 presents in 1/3 hour. how many presents can gabe wrap per hour? A store ships books by weight. A small box can hold 46 pounds. A medium box can hold 57 pounds. A large box can hold 89 pounds. The weights of the books are given below. Drag books into each box to show what it can hold. Darnell correctly compares the values of the digits in 644.66. Select the comparison Darnell could have made.A The value of the hundredths digit is 10 times the value of the tenths digit.B The value of the ones digit is one over ten the value of the tens digit.C The value of the tens digit is one over ten the value of the ones digit. DThe value of the hundreds digit is 100 times the value of the hundredths digit. 30.10A bag contains 4 red marbles, 3 a bag contains 4 red marbles, 3blue marbles, and 7 green marbles. If a marble is randomly selected from the bag,find the probability that a blue marble will be drawn A security alarm requires a four-digit code. The code can use the digits 09 and the digits cannot be repeated. What is the approximate probability that the code only contains odd numbers? 0.0005 0.00099 0.012 0.02381 which one of the following is the single best answer with regard to anaphylaxis?