John Snow studied cholera in London in the 1800s. He determine that the source of this epidemic was a contaminated well. In this example, the contaminated well was the


carrier.

host.

reservoir.

pathogen.

Answers

Answer 1

Answer:

C -- Reservior

Reservior -- a supply or source of something.


Related Questions

how do i solve this?

Answers

Answer:

57.6g

Explanation:

In the balanced equation H2O and Mg(OH)2 have the same coefficient (1) so we know that 3.2 moles of H2O react to form 3.2 moles of Mg(OH)2. Now we just have to calculate the mass of the H2O which we can do by finding the molar mass from the periodic table. For this just add the molar masses of the consituent atoms. (2(1)+1(16))=18g/mol H2O. Now that we know the molar mass we just have to multiply it by the amount of moles. 18*3.2=57.6g H2O

HELP ME PLEASE!!! WILL MARK BRAINLIEST!!

Answers

Answer:

See answers below

Explanation:

-44.3 kj/mole   *   x moles =  -  18.7 kj

solve for x = .422 mole  dissolved

Mole weight of  NaOH is

                     Na = 22.989     O = 15.999   H = 1.008    gm/mole

                            = ~~ 40 gm/mole   for NaOH

40 gm / mole   *  .422 mole = 16.88 gm  of NaOH

An air sample in an elastic bag has a volume of 3. 8 L when the temperature is 10 C. What will be the volume in liters when it is heated to 150 C?

Answers

[tex]\qquad\qquad\huge\underline{{\sf Answer}}[/tex]

At 10°C :

Volume = 3.8 L

Temperature (in Kelvin) :

[tex]\qquad \tt \dashrightarrow \: 10 + 273[/tex]

[tex]\qquad \tt \dashrightarrow \: 283 \: k[/tex]

Now,

Temperature in Kelvin (at 150° C)

[tex]\qquad \tt \dashrightarrow \:150 + 173[/tex]

[tex]\qquad \tt \dashrightarrow \:323 \: k[/tex]

Now, let's find the volume (x) [ assume pressure to be constant ]

[tex]\qquad \tt \dashrightarrow \: \dfrac{V_1}{T_1} = \dfrac{V_2}{T_2}[/tex]

[tex]\qquad \tt \dashrightarrow \: \dfrac{3.8}{283} = \dfrac{x}{323}[/tex]

[tex]\qquad \tt \dashrightarrow \: \dfrac{3.8}{283} \times 323 = {x}[/tex]

[tex]\qquad \tt \dashrightarrow \: {x} \approx4.34 \: \: litres[/tex]

File attached, i need an explanation too

33. Stan and Kenya are investigating the properties of gases in the lab. Stan has a balloon filled with helium, and Kenya has a balloon filled with hydrogen. Under which condition do the gases in the two balloons have the same kinetic energy?




same volume




same pressure




same temperature




same concentration

will give brainliest

Answers

If the sample of helium and nitrogen gas has the same kinetic energy, then it follows that hey have the same temperature.

Kinetic energy of gases

We know that gas molecuules are in constant random motion hence they collide with each other as well as with the walls of the container. The temeprature of the gas determines the kinetic energy of the gas.

Hence if the sample of helium and nitrogen gas has the same kinetic energy, then it follows that hey have the same temperature.

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What is the percent yield when a reaction vessel that initially contains 68.0 kg CH4 and excess steam yields 16.9 kg H2

Answers

When a reaction vessel initially containing 68.0 kg [tex]CH_4[/tex] and excess steam yields 16.9 kg [tex]H_2[/tex], the percent yield would be 49.8%

Percent yield

Recall that: percent yield = yield/theoretical yield x 100%

From the equation of the reaction:

[tex]CH_4 + 2H_2O --- > CO_2 + 4H_2[/tex]

The mole ratio of methane to steam is 1:4.

Mole of 68.0 kg methane = 68000/16.0 = 44239.4 moles

Equivalent mole of  [tex]H_2[/tex]= 16,957.6 moles

Mass of 16,957.6 moles  [tex]H_2[/tex] = 16,957.6 x 2 = 33,915.2 grams or 33.92 kg

Percent yield = 16.9/33.92 x 100% = 49.8%

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The percentage yield of the reaction that yields 16.9 kilograms of Hydrogen gas, H₂ is 66.3%

Balanced equation

CH₄ + H₂O —> CO + 3H₂

Molar mass of CH₄ = 16 g/mol

Mass of CH₄ from the balanced equation = 1 × 16 = 16 g = 0.016 Kg

Molar mass of H₂ = 2 g/mol

Mass of H₂ from the balanced equation = 3 × 2 = 6 g = 0.006 Kg

SUMMARY

From the balanced equation above,

0.016 Kg of CH₄ reacted to produce 0.006 Kg of H₂

How to determine the theoretical yield of H₂

From the balanced equation above,

0.016 Kg of CH₄ reacted to produce 0.006 Kg of H₂

Therefore,

68 Kg of CH₄ will react to produce = (68 × 0.006) / 0.016 = 25.5 Kg of H₂

How to determine the percentage yield Actual yield of H₂ = 16.9 KgTheoretical yield of H₂ = 25.5 KgPercentage yield =?

Percentage yield = (Actual / Theoretical) × 100

Percentage yield = (16.9 / 25.5) ×100

Percentage yield = 66.3%

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The reaction below consistently yields 82% of the theoretical value. If you need to make 10 g of Mg(OH)2 How much Mg3N2 (g) should you use (assume that you will use H2O in excess).

Mg3N2(s) + H2O(l) → Mg(OH)2(s) + NH3(g)
Help me please!

Answers

If excess [tex]H_2O[/tex] is used as stated in the illustration the amount of [tex]Mg_3N_2[/tex] that would be required would be 7.57 grams

Stoichiometric calculation

From the equation of the reaction:

[tex]Mg_3N_2(s) + 6H_2O(l) --- > 3Mg(OH)_2(s) + 2NH_3(g)[/tex]

Since the yield is 80% of the theoretical value, in order to make 10g, the theoretical yield would be 12.5 g.

Mole ratio of [tex]Mg_3N_2[/tex] and [tex]Mg(OH)_2[/tex] = 3:1

Mole of 12.5 g  [tex]Mg(OH)_2[/tex] = 12.5/53.32 = 0.225moles

Equivalent mole of [tex]Mg_3N_2[/tex]  = 0.124/3 = 0.075 moles

Mass of 0.0041 moles  [tex]Mg_3N_2[/tex] = 0.075 x 100.95 = 7.57 grams

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A conclusion drawn through reasoning is called an

evaluation
inference
oversight
understanding

Answers

a conclusion drawn through reasoning is called an inference

Which indicator displays orange in acidic solutions?
Universal indicator
Methyl orange indicator
Thymol blue indicator
Phenol red indicator

Answers

Answer:

Explanation:

Universal indicator. The universal indicator turns orange in acidic solutions with a pH of  

How does volume affect temperature and pressure?

Answers

Answer:

The volume of a given gas sample is directly proportional to its absolute temperature at constant pressure

Explanation:

When the temperature of a gas is kept constant, the volume of that gas is inversely proportional to its pressure. Equal quantities of all gases contain the same amount of molecules under identical temperature and pressure conditions.

How are transform boundaries different from
convergent and divergent boundaries?

Answers

Answer:

As the plates travel horizontally past one other, no crust is formed nor destroyed.

Explanation: tectonic plates

Scenario

HURRY I NEED HELP ASAP

A student masses 40 g copper (11) oxide Cuo, a black solid, and heats the substance using a Bunsen burner until the sample turns a reddish color. The chemical equation for the reaction issiven below. According to the reaction, the copper (1) oxide decomposes to produce copper(1) oxide and oxygen

4CuO → 2Cu2O + O2
Black solid Red solid Colorless gas

40 g. ? g
? g

Based on the evidence, write a scientific explanation describing the exact mass of the copper() oxide produced Provide mathematical evidence and give your reasoning in a way that demonstrates your understanding of the scientific principles involved.

Answers

72 g of Copper(i) oxide will be produced by 40 g of CuO base on the law of conservation of mass.

What mass of copper (i) oxide is produced?

The law of conservation of mass states that mass remains constant at the end of every reaction.

The equation of the reaction is given below:

[tex]4CuO → 2Cu_2O + O_2[/tex]

Based on the equation of reaction, 4 moles of copper (ii) oxide produces 2 moles of copper (i) oxide.

Mass of 4 moles of CuO = 4 × 80 = 160 g

Mass of 2 moles of copper (i) oxide = 2 × 144 g = 288 g

Mass of Copper(i) oxide produced by 40 g of CuO will be: 40 × 288/160 = 72 g

Therefore, 72 g of Copper(i) oxide will be produced by 40 g of CuO.

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Hazardous materials are grouped into classes identifying their.

Answers

Hazardous materials are grouped into classes identifying their similarities in composition and structure.

Why hazardous materials are grouped into classes?

The hazardous materials are grouped into classes in order to tell us about the severity of hazard and it is done on the basis of similarity in composition.

So we can conclude that hazardous materials are grouped into classes identifying their similarities in composition and structure.

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If 26.5 L of nitrogen at 748 mm Hg are compressed to 765 mm Hg at constant temperature. What is the new volume?

Answers

Answer:

25.91 L

Explanation:

P1V1= P2V2

748 (26.5) =  765 ( V2)      V2 = 25.91 LITERS  

Determine the volume of a balloon at STP assuming that it occupies a volume of 7.75 L at a temperature of 0ºC and a pressure of 125 kPa.

Answers

Answer:

v2 = 9.69L

Explanation:

p1 v1/t1 = p2 v2/t2

P = Pressure

V = Volume

T = Temperature

T = 273k

P = 1 atm

1.23 x 7.75/273k = 1xv2/273

The slashes I used represent as fractions. (:

Determine the mass of an object that has a volume of 88.6 mL and a density of 7.77 g/mL. 0.0877 g 80.8 g 96.37 g 688 g 11.4 g 10 points

Answers

Answer:

688g

Explanation:

This is the correct awnser

Give the full electron configuration for nitrogen.

Answers

Answer:

1s2 2s2 2p3

Explanation:

A chemical buffer is a solution that increases pH changes when small quantities of an acid or base are added. True False

Answers

Answer:

false

Explanation:

A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it. A buffer protects from ph increasing.

Chemical buffers are substances that are necessary to preserve the constancy of pH in various biological and chemical systems. Therefore, the given statement is True.

They are composed of either a weak base and its conjugate acid, or vice versa. The weak base component of the buffer reacts with the acid upon addition, reducing the pH rise. Similarly, when a base is added, the weak acid component of the buffer reacts with it to prevent the pH from falling significantly.

This ability to withstand pH variations is essential for preserving the proper operation of biological systems, such as blood pH in the human body, as well as in other laboratory and industrial operations where it is necessary to preserve a stable pH for best results.

Therefore, the given statement is True.

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In many titrations, you need to add an indicator that changes color when the titration is complete. The titration of sodium oxalate with potassium permanganate does not use an indicator. However, a pink color does appear to signal the end of the titration. What causes the color change signaling the completed titration of sodium oxalate with potassium permanganate?.

Answers

In the titration of sodium oxalate with potassium permanganate the pink color change is due to shift in equilibrium position of the reaction

What is chemical equilibrium?

Chemical equilibrium is the equilibrium that exists between chemical species in which the rate of forward reaction is equal to the rate of backward reaction.

The pink color change in the that occurs in the titration of sodium oxalate with potassium permanganate is due to shift in equilibrium position of the reaction.

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Simple question.
Why do tsunamis do most of their damage onshore, and not in the middle of the ocean?

Answers

Answer:

im assuming its due to something like water on water not eing as bad as the thwap of water on land. this wasnt a test question was it?

Explanation:

Answer:

As the tsunami waves become compressed near the coast, the wavelength is shortened and the wave energy is directed upward - thus increasing their heights considerably. Just as with ordinary surf, the energy of the tsunami waves must be contained in a smaller volume of water, so the waves grow in height. and they can't do damage out in the middle of the ocean because there is not much to damage out in sea  

Explanation:

Types of isomers possible for ch3 ch2 ch2 ch3

Answers

Answer:

It has two isomers; n-butane and isobutane. Here n-butane is a straight-chain compound with four carbon atoms bonded with single covalent bonds. Explanation: Butane is an alkane with four carbon atoms so molecular formula is C4H10.

Explanation:

A student places a starch and water solution into a bag of dialysis tubing and then ties off the ends. Next, he places the filled bag into a beaker of distilled water. Water will now ________ the bag by the process of ________.

Answers

Answer:

After 30 minutes have passed, the solution inside the dialysis tubing and the solution in the beaker will be tested for glucose and starch

-The presence of glucose will be tested with Benedict's solution, Testape®, or Clinistix

What is the best method for monitoring the progress of reaction during the oxidation reaction of borneol to camphor

Answers

Answer:This reaction will be followed by TLC to monitor the progress of the oxidation. The camphor is then reduced by sodium borohydride to give the isomeric alcohol,

Explanation:

hopes this helps<33

how many moles of water are needed to react with 2.3 grams of sodium

Answers

Answer:

Brainliest pls

Explanation:

Theoretical yield = 0.1 g

Percent yield = 80%

Which factor varies between the isotopes of an element?.

Answers

Answer:

neutron number

Explanation:

^

Why do hospitals use saline instead of distilled water?.

Answers

Explanation:

Normal saline contains Na+ and Cl-. Extracellularly,there is more Na+ and Cl- than intracellularly and most often during loss of bodily fluid,it is extracellular fluid that is lost and so the Na+ and Cl- ions in saline replenish these. Even if the loss of fluid is intracellular,it can still be replenished (passively )from the extracellular fluid into the intracellular fluid. Conversely, distilled water is just water which lacks any special electrolytes to carry out these functions as the normal saline

which will get spoiled faster: plum in water or plum in the open?

Answers

Answer:

It depends

(plum will spoil more quickly at warm temperatures)

Explanation:

why is the speed of these particles deffirent in each state

Answers

Answer:

due to difference ic kinetic energy

Explanation:

True or false The reaction is fastest when few bubbles are being produced.

Answers

Answer:

no, it is fastest when many bubbles are produced.

Explanation:

Which reaction would cause a decrease in entropy?
A. 2NOCI(9) + 2NO(g) + Cl2(9)
B. 2NH3(9) ► N2(g) + 3H2(9)
C. 2CC14(9) + O2(g) → 2C0C12(g) + 2Cl2(9)
D. CO(g) + 3H2(g) → CH4(9) + H20(9)

Answers

2NOCI(9) + 2NO(g) + Cl2(9) shows decrease in entropy.

What is Entropy?

Entropy in thermodynamic refers to the degrees that represent the absence of system's thermal energy that is not available to perform mechanical work, which is the degree of disorder or randomness in the system.

Therefore, 2NOCI(9) + 2NO(g) + Cl2(9) shows ddecrease in entropy because it shows degree of disorderliness is low

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Scientists used to believe that chemical reactions fueled the sun. Why did this lead them to believe that the sun was very young? What kind of reactions do we now think are responsible for the energy released by the sun? In one to two sentences , explain your reasoning 2 points )

Answers

The energy produced by the sun is as a result of nuclear reactions which produces large amounts of energy.

What are chemical reactions?

Chemical reactions are reactions which occur as a result of a rearrangement of atoms of elements to form new combinations of substances known as compounds.

Since chemical reactions which have relatively short lifespans, scientist would have assumed that the sun is very young.

However, nuclear reactions have been proven to be the means by which the sun produces its energy.

Nuclear reactions release large amounts of energy and have relatively long lifespans.

Therefore, the energy produced by the sun is as a result of nuclear reactions.

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Which second degree polynomial function f(x) has a lead coefficient of 3 and roots 4 and 1? f(x) = 3x2 5x 4 f(x) = 3x2 15x 12 f(x) = 3x2 5x 4 f(x) = 3x2 15x 12 1. List three consequences of the global economic crisis that began in 2008.a. Financialb.C.2. The rapid spread of thecurrent economic crisis is directly related to the PART B: Which of the following quotes best supports the answer to Part A? A. "I really think that the people who buy these books (if any people do buy them) have a moral, if not a legal, right to ask for their money back." ( Paragraph 1) B. "Beyond the rules of the game it is all a question either of talent or dishonesty; and I will undertake to provide either one or the other" ( Paragraph 2) C. "He merely wished to prostrate himself before the mystery of a millionaire. For when we really worship anything, we love not only its clearness but its obscurity." ( Paragraph 4) D. "They do not teach people to be successful, but they do teach people to be snobbish; they do spread a sort of evil poetry of worldliness." ( Paragraph 7) Which of the following living reptiles care for their young and have a four-chambered heart, as birds do?a. Turtlesb. Crocodilesc. Lizardsd. Snakese. Tuataras 3.Read these sentences from paragraph 7. The hour was approaching at which the continental breakfast begins, or rather ceases, to tell, and the ladies bought some hot chestnut paste out of a little shop, because it looked so typical. It tasted partly of the paper in which it was wrapped, partly of hair oil, partly of the great unknown.The tone of this paragraph can best be described as distressedanxioustranquilenthusiastic A philanthropist pledges to donate 18% of afund each year. If the fund initially has$699,000.00, how much will the fund haveafter 8 years? 60 units needed 14 units per case Gabrielle lives 24 miles from where she works, Leaving work, she drives at a speed of 45 miles per hour for 11 minutes. If Gabriellecontinues driving at this speed, how many more minutes will it take her to get home? ASAP PLEASEHELP ME WILL GIVE 50 POINTS AND MARK BRAINLIESTA company has released the following possible designs for a new cereal box. The cost of production depends upon the cost of materials, which is determined by how much material is used. The amount of material used is equal to the surface area of the package plus some overlap. The amount of product contained in the package is the volume of the packaging.Find the surface area and volume of the following possible cereal boxes. Determine the cost of making the cereal box assuming that cardboard costs $0.05 per square inch. What is the area, in square feet, of the rectangle shown below? A puck moves 2.35 m/s in a -22 degree direction. A hockey stick pushes it for 0.215 s, changing its velocity to 6.42 m/s in a 50 degree direction. What is the magnitude of acceleration Suzie paid a total of \$324$324dollar sign, 324 for xxx tickets to a rock festival. How much did each ticket cost?Write your answer as an expression At lunch, kira eats either a burrito containing 490 milligrams of sodium or a peanut butter sandwich containing 700 milligrams of sodium. her doctor told her to reduce her sodium to no more than 4,000 milligrams per week. which inequality represents x, the number of microwave burritos, and y, the number of peanut butter sandwiches, she can eat each week? 490x 700y < 4000 490x 700y 4000 490x 700y > 4000 490x 700y 4000 Pls help with math pls will give brainlest due soon PLEASE HELP ASAPThe dot plot represents the number of points students scored playing ring toss at the school fair. Each dot represents one student.The school administrator wants one number to summarize all the values of the data set, so she should find a measure of_____. To summarize all the values of the data set with one number, she can calculate the____or the____of the data set. Why can't you see the orbits of Earth, Mercury, Venus, and Mars in the diagram of the solarsystem? In the model of energy flow from autotrophs to heterotrophs, the interaction of matter and energy at different levels of the foodweb is shown. Which statement accurately describes the energy transfer, the process involved, and the products formed based onthe model? An equation is shown below:5x + 3(x 5) = 6x + 2x 15Part A: Solve the equation and write the number of solutions. Show all the steps. (6 points)Part B: Name one property you used to solve this equation. (4 points)Your answer: What type of task can be defined to allow you fine-grained control over the management tasks a user can perform in an OU What did the marshall plan and comecon have in common?.