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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 1

Answer:

The answer is option A.

its reactivity

I hope this helps you.

Answer 2

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!


Related Questions

An aqueous solution of glucose (MM = 180.2 g/mol) has a molality of 2.27 m and a density of 1.20 g/mL. What is the molarity of glucose in the solution?

**Any help would be greatly appreciated!**

Answers

Answer:

Molarity of the glucose solution = 2.72 mol/L

Explanation:

Molality of a solution is defined as the number of moles of solute per kilogram of solvent.

Therefore , a 2.27 molal solution of glucose contains 2.27 moles of glucose in 1 Kg of solvent

Density of solution = 1.20 g/mL

The volume occupied by 1 Kg or 1000 g solution = mass/density

Volume of 1000 g solution = 1000 g/1.20 g/ml = 833.3 mL

Number of moles of glucose present in the solution = 2.27 moles

Molarity = number of moles / volume(L)

volume of solution in litres = 883.3/1000 = 0.8333 L

Molarity = 2.27 moles /0.8333 l = 2.72 mol/L

Therefore, molarity of the glucose solution = 2.72 mol/L

The molarity of the glucose in the solution has been 2.72 mol/L.

Molality can be defined as the moles of the solute per kg of solvent.

The molality of glucose solution = 2.27 m

2.27 moles of glucose in 1000 grams of water.

Density has been the mass per unit volume. The density can be expressed as:

Density = [tex]\rm \dfrac{Mass}{Volume}[/tex]

The density of the given glucose solution = 1.20 g/ml

The volume of 1000 grams of water has been:

Volume = [tex]\rm \dfrac{Mass}{Density}[/tex]

Volume of 1000 grams water = [tex]\rm \dfrac{1000\;g}{1.20\;g/ml}[/tex]

Volume of 1000 g water = 833.3 ml

The molarity can be defined as the mass of solute per liter of the solution.

Molarity = [tex]\rm moles\;\times\;\dfrac{1000}{Volume\;(ml)}[/tex] ......(i)

The moles of glucose in the 833.3 ml solution have been 2.27 mol.

Substituting the values in equation (i):

Molarity = 2.27 mol [tex]\rm \times\;\dfrac{1000}{833.3\;ml}[/tex]

Molarity = 2.72 mol/L.

The molarity of the glucose in the solution has been 2.72 mol/L.

For more information about the molarity of the solution, refer to the link:

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In Act V, scene ii of Romeo and Juliet, what role does Friar John play in the catastrophe?

He creates a quarantine, which impacts Romeo.

He secretly performs Romeo and Juliet's wedding.

He mistakenly tells Balthasar that Juliet is dead.

He fails to deliver an important letter to Romeo.

Answers

Answer:

I believe its the 4th one. He goes to give Romeo the message but before he is able to, Balthasar tells Romeo that Juliet is dead. Friar John just wasn't there in time.

Answer:

D) he fails to give Romeo an important letter

Explanation:

i took the test. edge 2020

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)

Which is one way that analyzing ice benefits scientists who study ancient climates? Scientists can analyze frozen volcanic dust to help predict eruptions. Scientists can drill deep into the ice to collect ice cores. Scientists can use pollen grains in ice to make inferences about the climate area. Scientists can study tree rings in ice to learn more about past climates.

Answers

Answer:

The correct option is;

Scientists can drill deep into the ice to collect ice cores which contain trapped atmospheric gases

Explanation:

The study of past climates also known as paleoclimatology, is accomplished by acquiring information from proxy data sources which are physical environment characteristics that are preserved through time to remake the conditions of past climate

Past physical environmental characteristics, from which information about ancient climate can be gained are stored in nature's climate variability records including, ice cores, rings in tree stems, fossil pollen, sediments found in the waters of the ocean

The proxy sources provide a means of understanding the conditions of ancient climate before advent of climate measurement.

Therefore, one way that analyzing ice benefits scientists who study ancient climates is that scientists can drill deep into the ice to collect ice cores which contain trapped atmospheric gases from past climates.

Answer: B: Scientists can study the layers of ice cores to gather information about past atmospheric composition.

Explanation: Got it right on a test!

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:

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Which example is a long-term environmental change? La Niña El Niño climate change small asteroid impact

Answers

The correct answer is C. Climate change

Explanation:

Long-term environmental changes occur as major events affect the environment and ecosystems indefinitely. These events differ from short-term environmental changes because the effect of short-term environmental changes is mainly temporary. Also, long-term changes are usually gradual.

Climate change is an example of long-term environmental changes because this implies indefinite and major changes in weather patterns and ecosystems. For example, it is believed climate change will decrease the amount of ice in Earth, change sea level, and lead to the extinction of dozens of species. This does not occur with events such as el niño or a small asteroid impact that affect the environment for a short time and do not imply major changes.

Answer:

it is c) climate change

Explanation:

i just took the quiz

hope this helps!!!   :D

What is the best definition of chemistry?
A. The study of mass, energy, and light
B. The study of life and energy
C. The study of experiments and theories
D. The study of matter, its properties, and its reactions

Answers

D the study of matter, it’s properties, and it’s reactions
The study of matter its properties and its reactions

What is chemical potential energy?

Answers

Answer:

Chemical potential energy is the energy stored in the chemical bonds of a substance.

Explanation:

C AL= -4.184 × 39.85 × 4.7 ÷ 11.98 × (-72.9)

Answers

Answer:

4,768.57

Explanation:

If you are asking us to calculate, your answer is above. Easiest and fastest way is to plug it into the calc.

4,768.57 is what I think the answer is

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.

Which is a negative effect of deforestation on the environment? habitat restoration, desertification, soil production, or urbanization

Answers

Answer:

The correct option is desertification

Explanation:

Deforestation is the deliberate act of pulling down trees to provide a clear land for space or to make use of the trees for other purposes  such as grazing, farming, timber fire wood, building and constructions, urban utilization, access roads, expansion, development of infrastructures, grazing of cattle and mining

The effects of deforestation includes climate change, flooding, increase in the proportion of green house gases in the atmosphere, soil erosion and desertification.

A negative effect of deforestation is desertification.

Deforestation refers to the cutting down of trees. There are many reasons why people may cut down trees. One of the popular reasons why people cut down trees is to obtain timber which is used for construction and as fuel.

An important consequence of the felling of trees also called deforestation is that a once fertile land may gradually be turned into a desert area. This is known as desertification.

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Boiling point of water at 750 mmHg is 99.63⁰C. How much sucrose is to be added to 500 g of water such that it boils at 100⁰C. Kb for water 0.52 K Kg mol-1

Answers

Answer:

121.67 g is to be added to 500 g of water

Explanation:

Given that:

Pressure = 750 mmHg

Temperature T₁= 99.63⁰C = (273 + 99.63 ) = 372.63K

mass of water = 500 g

Temperature T₂  = 100⁰C = ( 273 + 100) K = 373 K

where;

Kb for water 0.52 K Kg mol-1

For sucrose; C₁₂ H₂₂ O₁₁

Molar mass =  ( 12 × 12 )+ ( 1 × 22 ) + ( 16 × 11 )

Molar mass = 342 g/mol

ΔT = T₂  - T₁

ΔT = (373 - 372.63)K

ΔT = 0.37 K

∴ the amount of sucrose to be added to  500 g of water is:

 [tex]= \dfrac{0.37\times 342 \times 500}{0.52 \times 1000 }[/tex]

[tex]= \dfrac{6327}{52}[/tex]

= 121.67 g

Thus; 121.67 g is to be added to 500 g of water

What type of compound are carbon tetrachloride and boron trihydride?

Answers

Answer:

hydrocarbon

Explanation:

these are called hydrocarbons

which of the following us not a property of salt in the ionic and covalent properties lab

Answers

Explanation:

I think Low melting point

because NaCl (salt has mp 801 degC)

Water has mp 0 degC

Why does carbon form covalent bonds?

Answers

Answer:

Carbon has 4 electrons in its outermost shell. ... Therefore, carbon completes its octet by sharing its 4 electrons with other carbon atoms or with atoms of other elements and forms covalent bond. It forms strong covalent bonds because of its small size.

Explanation:

heterogeneous non example

Answers

Heterogeneous 'mixtures' (because they don't meet the definition  of mixtures) are mixtures substances that aren't completely uniformly spread out. They haven't reacted with the solvent to become a solution.

Explanation: There are 2 types of heterogeneous solutions, A Colloid and a suspension.

Colloid: You can check if a mixture is heterogeneous by passing a light ray through it. This may cause the Tyndall effect (If the mixture is a colloid) when the Colloidal Heterogeneous mixture's particles are so small that they refract the beam of light and the path of light will be visible, like if you add 3 drops of milk in a glass of Water and shine a laser light through it. This is because the particles are too small to be seen by the unaided eye but big enough to scatter you laser light. However that particles won't settle down or will be separated by a filter paper due to particles' small size.

Suspension: A solution will be a solution when the particles of the Mixture is big enough to be seen by the unaided eye. Like if you mix sand and Water, the sand will eventually settle down due to Gravity. The mixture's solute will be big enough to pass through a filter paper.


1 Cup of Boiling Water
WAPHS Swimming Pool
(100 °C)
or
(25 °C)
• What is the difference between thermal energy and
temperature?
aterials
Enosh
Odates
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endance
mbers
• The boiling water has a much higher temperature... What
does that mean?
nferences
enuity Ele
enuity se
sela
• Which has more thermal energy? Why?
Note Cla
Learnir
9
1 Mop

Answers

Answer:

Side photo

A small still is separating propane and butane at 135 °C, and initially contains 10 kg moles of a mixture whose composition is x = 0.3 (x = mole fraction butane). Additional mixture (x = 0.3) is fed at the rate of 5 kg mole/hr. The total volume of the liquid in the still is constant, and the concentration of the vapor from the still (xp) is related to x, as follows: Xp = How long will it take for X, to change from 0.3 to 0.35.

Answer: A swimming pool at 40°C is at a lower temperature than a cup of tea at 90°C. However, the swimming pool contains a lot more water. Therefore, the pool has more thermal energy than the cup of tea even though the tea is hotter than the water in the pool.

Explanation: Heat and Temperature do not mean the same thing. ... A swimming pool at 40°C is at a lower temperature than a cup of tea at 90°C. However, the swimming pool contains a lot more water. Therefore, the pool has more thermal energy than the cup of tea even though the tea is hotter than the water in the pool.

The image is of the formation of a fault-block mountain.
Which of these most likely occurs to result in the
formation of these mountains?
O The crust is compressed
O The crust does not spread apart
The center block is forced upward.
The hanging walls from the two parallel faults slip down​

Answers

Answer:

d.

Explanation:

The Formation of these mountains will be caused by

The crust does not spread apartThe center block is forced upward.The hanging walls from the two parallel faults slip down​

Options B, C, and D is correct.

What are mountains?

Generally, a mountain is simply defined as a body that rises dramatically above its surroundings and is distinguished by steep slopes.

In conclusion, Mountains are formed from the formation of rocks over years in an Environment.

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Fredo’s spaceship takes him to the very edge of known space. There, gravity has no effect at all. Fredo takes a baseball and tosses it into space. What will most likely happen to the ball? It will not move at all. It will return to Fredo’s spaceship. It will eventually stop moving. It will continue moving in a straight line.

Answers

Answer:

D. It will continue moving in a straight line.

Explanation:

When Fredo takes a ball and tosses it into space, the ball will move upward infinitely.

Gravity is the downward force that acts on an object.

Without gravity, or without the effect of gravity, an object will continue to move in its path with the original direction applied to it.

Answer:

D

Explanation:

I took the test

why am i blonde.............

Answers

Answer:

because your parents carry the recessice gene or they are blond

Explanation:

it could also be ffrom a mutation or just because you dyed your hair

A student weighs out a 6.64 g sample of , transfers it to a 500. mL volumetric flask, adds enough water to dissolve it and then adds water to the 500. mL tick mark. What is the molarity of cobalt(II) fluoride in the resulting solution

Answers

Answer:

the molarity of cobalt(II) fluoride in the resulting solution is = 0.137  M

Explanation:

Given that :

a student dissolves 6.64 g of CoF₂  into 500 mL of water

volume of the solution(water) = 500 mL = 0.50 L

The standard  molar mass of CoF₂ is 96.93 g/mol

number of moles of CoF₂ = mass of CoF₂/molar mass of CoF₂

number of moles of CoF₂ = 6.64 g/96.93 g/mol

number of moles of CoF₂ = 0.0685 mol

The molarity of any given substance is known to be as the number of moles of solute dissolved in one litre of solution.

Thus ;

Molarity of  cobalt(II) fluoride CoF₂ in the resulting solution is = number of moles / Volume in (L)

Molarity of  cobalt(II) fluoride CoF₂  = 0.0685 mol/ 0.50 L

= 0.137  M

Thus ; the molarity of cobalt(II) fluoride in the resulting solution is = 0.137  M

En la electrólisis del Cloruro de plomo se han depositado 2.6 gramos del metal en 20 minutos el peso atómico del plomo es 206 calculo la intensidad de la corriente eléctrica empleada AYUDENNNNN PLISSSS es para hoy!!!!!

Answers

Answer:

2.01 A

Explanation:

Para esta pregunta debemos empezar por la semi-reaccion del plomo:

[tex]Pb^+^2~_(_a_q_)~+~2e^-~->~Pb_(_s_)[/tex]

Se intercambian dos electrones en la semi-reacción del plomo. Si tenemos en cuenta la ecuación:

[tex]n=\frac{I*t}{z*F}[/tex]

Donde:

n= Moles depositados

I= Intensidad de corriente (en Amperios)

z= Numero de electrones intercambiados

F= Constante de faraday = 96484 C/mol

t=tiempo (en segundos)

Que conocemos de esta ecuación?

Los moles (se pueden calcular a partir de la masa atómica del plomo, 207.2 g/mol)

[tex]2.6~g~Pb\frac{1~mol~Pb}{207.2~g~Pb}=0.0125~mol~Pb[/tex]

El tiempo (hay que convertirlo a segundos):

[tex]20~min\frac{60~s}{1~min}=1200~s[/tex]

Z (Numero de electrones)

De acuerdo a la semi-reacción son intercambiados 2 electrones.

Por lo tanto podemos resolver para "I":

[tex]I=\frac{n*z*F}{t}=\frac{0.0125~mol*2*96484\frac{C}{mol}}{1200~s}[/tex]

[tex]I~=~2.01~\frac{C}{s}=2.01~A[/tex]

Espero que sea de ayuda!

Polarity of water. Which is the correct answer?

Answers

The correct answer will be the first one, promotes the formation of hydrogen bonds.

This is the reaction of “the polarity of water molecules”

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.

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:

ON A TIMER!!! PLZ HELP ME!!!
Consider the reaction below. *Image* Which is the net ionic equation for the reaction?

Answers

Answer:

C2H3O2^-(aq) + H^+ —> HC2H3O2

Explanation:

The following equation was given in the question:

Na^+ + C2H3O2^-(aq) + H^+ Cl^- —> Na^+ + Cl^- + HC2H3O2

Now, to obtain the net ionic equation, we simply cancel out the ions common to both side of the equation.

A careful observation of the equation above, shows that sodium ion, Na^+ and chloride ion, Cl^- are common to both side of the equation.

Therefore, to obtain the net ionic equation, we simply cancel out Na^+ and Cl^- from both side of the equation. This is illustrated below:

Na^+ + C2H3O2^-(aq) + H^+ Cl^- —> Na^+ + Cl^- + HC2H3O2

C2H3O2^-(aq) + H^+ —> HC2H3O2

Therefore, the net ionic equation is

C2H3O2^-(aq) + H^+ —> HC2H3O2

Balance the chemical equations

Answers

Answer:

Explanation:

1).  Ca(NO₃)₂ + KI → CaI + K(NO₃)₂

    This equation is incorrect.

    When Ca⁺⁺ reacts with I⁻, final product is CaI₂

    And when K⁺ react with NO₃⁻, final product is KNO₃

    Hence the equation will be,

    Ca(NO₃)₂ + KI → CaI₂ + KNO₃

    Now we have to balance this equation.

     Ca(NO₃)₂ + 2KI → CaI₂ + KNO₃

                          ↓

     Ca(NO₃)₂ + 2KI → CaI₂ + 2KNO₃

2). Ca(NO₃)₂ + KOH → CaOH + K(NO₃)₂

    This equation is incorrect,

    Since the reaction of Ca⁺⁺ with OH⁻ gives the final product     Ca(OH)₂

    And final product of K⁺ and NO₃⁻ is KNO₃

    Therefore, the equation will be,

    Ca(NO₃)₂ + KOH → Ca(OH)₂ + KNO₃

    Now we will balance this equation by changing the coefficients of the      molecules until the number of atoms on both the sides become equal.

    Ca(NO₃)₂ + KOH → Ca(OH)₂ + 2KNO₃

                                ↓

     Ca(NO₃)₂ + 2KOH → Ca(OH)₂ + 2KNO₃

3). Ca(NO₃)₂ + Na₂C₂O₄ → CaC₂O₄ + 2Na(NO₃)₂

    This equation is incorrect,

    Since the reaction of Na⁺ and NO₃⁻ gives the final product    NaNO₃.

    Therefore, the correct equation will be,

    Ca(NO₃)₂ + Na₂C₂O₄ → CaC₂O₄ + 2NaNO₃

     This equation is in the balanced form.

Which statement correctly describes a feature of the rock cycle?
PA
Rocks are preserved through the process.
Rocks change from one type to another.
Different rock groups are not related to one another.
Rocks change from one type to another in a specific order.

Answers

Answer:

It’s D

Explanation:

Answer:

D Rocks change from one type to another in a specific order.

Explanation:

How many moles of silver are equivalent to 2.408 x 10^24 atoms

Answers

i found this i hope this helps you

The mole is used to measure small particles like atoms and molecules.  The 4 moles of silver is equivalent to [tex]\bold{2.408 x 10^2^4 }[/tex] atoms.

Given here,

The number of atoms

[tex]\bold{2.408 x 10^2^4 }[/tex]

Number of moles = ?

1 mol of substance = [tex]\bold{ 6.02 x10^2^3}[/tex]

Hence,

moles of silver,

[tex]\bold {= \dfrac {2.408 x 10^2^4 } { 6.02 x10^2^3} }}\\\\\bold {= 4 mol}[/tex]

Therefore, the 4 moles of silver is equivalent to [tex]\bold{2.408 x 10^2^4 }[/tex] atoms.

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What molecule can form hydrogen bonds with others like it A. CF4 B. HCL C. CO2 D. NH3

Answers

Answer:

D. NH3

Explanation:

Hydrogen bonding exists only between hydrogen atoms, and is one of the strongest intramolecular forces. So you eliminate your choices down to B and D. HCl can't form Hydrogen bonding because of electron density and electronegativity but NH3 can, so your answer would be D.

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what sentence describes all atoms of one element A. They have the same number of isotopes B. They have the same properties C. They have the same number of protons D.They have the same number of neutrons Two oxide of sulphur,A and B were analyzed and the results obtained showed that in oxide A,3.50g of sulphur combined with 6.00g of oxygen and in oxide B,2.80g of sulphur combined with 9.55g.Show that this result illustrate the law of multiple proportion Which of the following scenarios best illustrates bundling? Cumulus Media Inc. sells its cloud computing network by having customers pay for the service as they use it. Fresh Seeds Inc. sells seed packages, in which a person can buy a package of three types of seeds at a discounted price compared to buying the seeds individually. Sharp Cable Inc. sells its basic TV channels for free but charges high prices for any channels that customers add on later. Clean Brush Inc. sells its electric toothbrushes for a low cost, but charges a high price for replacement brushes. The ___________ was first discovered by Norwegians. Larsen B Ice Shelf Antarctic Peninsula South Pole Ross Ice Shelf Explain whether the following statement is true or false. There is no mark for stating true or false; the mark is awarded for the explanation and the illustration only.One way in which monopolistic competition differs from oligopoly is there are no barriers to entry in oligopolies.Immersive Reader HELP PLS!!! ITS DUE ASAP AND I NEED HELP ITS THE LAST QUESTION "Pros and Cons of technology in education and healthcare The tape diagram represents an equation. Write an equation to represent the image. Who is speaking in this excerpt? Paul Revere Paul Reveres friend a British soldier a townspers a certain volume of dry air at NTP is allowed to expand five times of it original volume under adiabatic condition.calculate the final pressure.(air=1.4) Estimate how many arteries branch off the aorta given that arteries have a diameter of 0.4 cm and a flow speed of 45 cm/s. For each of the compounds, find the length of the longest carbon chain in the box provided.CH,CH3 -CH2-CH2-CH2-CH-CH2-CH2 - CH2 - CH3CH,CH,CH,HCCH-CH2-CH3CH,CH.CHCCH,CH,CH,1CH2H.C CH.CHCH3 Reflective clinicians often absorb the tenets and techniques associated with major theoretical approaches to counseling and then interpret and organize them in ways that are useful for their own work. This aspect of reflective practice is an example of a number cube numbered 1-6 is rolled 30 times and lands on an even number 18 times. How does this frequency compare to the expected frequency based on the probability of the number cube landing on an even number? Does Walter Mitty buys a pair of glasses? O TrueO False Which of these sets of points lie within plane w?A.Cand GB.Hand EC.C and EDA and D A monopoly, or exclusive control of an item, would create for the people in control, because of theirability to dictate the price of that item.A. wealthB. large supplyC. low demandD. a war Solve 6 + 5 2 4 9 2 x = 7 The process of generation of force by the high speed that pushes the jet engine forward is based on Newtons _____ law of motion ? Amy has opened a new startup company in web design. Within the first month of business, the startup agrees to maintain an accounting firm's website in exchange for someone at the firm doing the startup's tax returns. Which of the following principles of economic interaction best describes this scenario? a) Trade can make everyone better off. b) When markets do not achieve efficiency, government intervention can improve overall welfare. c) Markets allocate goods effectively. d) All costs are opportunity costs.