50 POINTS: PLEASE ANSWER AS QUICK AS POSSIBLE!

Question:

After getting their results in, a group of scientists went back and looked at their study. As planned, their experiment consisted of three groups. The first group received a new medicine at a normal dose, the second group received the medicine at half the dose, and the third group received the medicine at twice the dose.

Which of the following best describes what went wrong with the scientists’ study?


Choices:

- an improper experimental procedure

- the lack of a control group

- selection bias

- human error

Answers

Answer 1

Explanation:

The lack of a control group

Answer 2
The answer would be “the lack of a control group.” To make the results more accurate, the scientists should have used a placebo group to use as a comparison.

Related Questions

Why is the nitrogen cycle considered a closed system?

Answers

Answer:

because nitrogen is fixed by bacteria and assimilated by plants

Explanation:

Answer:

It is a considered a closed system because nitrogen is fixed by bacteria and is taken in by plants.

Explanation:

A metal object has a density of 2 g/ml. When placed in a graduated cylinder with 500 ml of water, the
water rises to 508 ml. What is the mass of the metal object?

Answers

Answer:

The answer is 16 g

Explanation:

The mass of a substance when given the density and volume can be found by using the formula

mass = Density × volume

From the question

density = 2 g/ml

volume = final volume of water - initial volume of water

volume = 508 - 500 = 8 mL

We have

mass = 2 × 8

We have the final answer as

16 g

Hope this helps you

what unit of measure would i use to measure the width of my fingernail A millimeters
B centimeters C meters D kilometers
E grams​

Answers

A. Millimeters
Because the width of fingernails are very small and millimeters is the smallest unit of measurement listed.

How many moles are in a sample of 2.39 x 10^23 atoms of sodium (Na)

Answers

Answer:

The answer is 0.4 moles

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\ [/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

[tex]n = \frac{2.39 \times {10}^{23} }{6.02 \times {10}^{23} } \\ = 0.39700996...[/tex]

We have the final answer as

0.4 moles

Hope this helps you

What is the relationship between the latitude and hours of daylight

Answers

Answer:

The tilt of the Earth's axis also defines the length of daylight.Daylight hours are shortest in each hemisphere winter. Between summer and winter

solistice the number of daylight hours decreases and the rate of decrease is larger the higher the latitude.The fewer sunlight hours the colder nights.

Which of the following is the correct model of C7H16?
A.
B.
C.
D.

Answers

Answer:

D

Explanation:

Option D gives the correct model of C7H16. From the option, one will discover that the model has 7 carbons in the backbone. If you count the attached hydrogen, you will discover that the hydrogen is 16 in total.

This model or skeletal structure of this element represents heptane. Heptane or n-heptane is known to be a straight-chain compound and an alkane. It's chemical formula can also be written as: H₃C(CH₂)₅CH₃ or C₇H₁₆.

This compound is known to be one of the main components of gasoline. It is known to be a volatile organic compound and a clear and colorless liquids with a petroleum-like odor.

Answer: D

Explanation: Just took the test

6. Now, revise your definition for waves to include energy and matter.

A wave is a phenomenon that...

Answers

Answer:

A wave is phenomenon that transfers energy from one point to another through a disturbance without affecting the matter.

Explanation:

A wave is phenomenon that transfers energy from one point to another through a disturbance without affecting the matter.

There are two main types of waves Longitudinal waves travels parallel to their source. For example, sound waves. Through a series of rarefactions and compressions, longitudinal waves are propagated. Transverse waves travel perpendicular to their source.

Aquanauts explore the area called?

Answers

Answer:

Inner space

Explanation:

I hope this helps

25 cm of liquid 'A' and 20 cm of liquid
'B' are mixed at 25°C and the volume of
solution was measured to be 44.8 cm3
then correct reaction is
(A) A Hmix = 0, solution shows
ideal

Answers

Answer:

The correct option is;

(B) [tex]\Delta H_{mix} < 0[/tex], solution shows negative deviation

Explanation:

The given parameters are;

The available volume of liquid A = 25 cm³

The available volume of liquid B = 20 cm³

The volume of the solution (mixture) = 44.8 cm³

Therefore, we have;

[tex]\Delta _{mix} V < 0[/tex]

Which is one of the prerequisite for the formation of negative deviation

When a non-ideal solution shows negative deviation according to Raoult's Law, we have;

[tex]\Delta _{mix} H < 0[/tex], we have more heat released due to new molecular interactions.

Need help ASAP please

Answers

Answer:Melting can create steam, kind of like a nukeular plant exept no nukulear rods

1. Endothermic; increases
2. Exothermic; decreases
3. Endothermic;increases
4. Exothermic; decreases
5. Endothermic; increases

What is force and motion

Answers

force is a strength or energy as an attribute or physical action or movement, motion is the action or process of moving or being moved

Answer:

In physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes beginning moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull.

= google

lol

What suprising result is explained using this model

Answers

Answer:

B. A few positive particles bounced back because they were pushed away from the positive center.

Explanation:

The result of the experiment conducted by Rutherford shows that a few positive particles bounced back because they were pushed away from the positive center.

This is the central theme of Rutherford's experiment on a thin gold foil.

In 1911, Rutherford performed the gold foil experiment that gave the modeling of the atomic structure a great boost. He bombarded a thin gold foil with alpha particles. He discovered that most of the alpha particles passed through the foil while a few of them were deflected back. This led him to postulate that an atom has a small positively charged center where nearly all the mass is concentrated.

Write the word equations for the following balanced chemical equations.
a. Zn + 2HCl → ZnCl2 + H2
b. 2503 2502 + O2

Answers

Answer:

21

Explanation:9+10

Convert 122 moles of Methane to liters?

Answers

122 moles of Methane to liters is 2734.5

How many electrons are there in the only energy level of helium, a noble gas? * Two Three Six Eight​

Answers

Answer:

Explanation:

Noble gases are the least reactive of all known elements. That's because with eight valence electrons, their outer energy levels are full. The only exception is helium, which has just two electrons.

Which phrase best describes igneous rocks?
form when lava and magma cool

accumulate sediments following erosion

require heat and pressure to be formed

consist of many sediment layers
ctivity

Answers

Answer:

A) form when lava and magma cool

please give me brainliest :p

God bless!

Answer:

A: form when lava and magma cools

Explanation:

Got it right on Edge 2020 :)

-79.6 -80 -81.2. is the correct answer

Answers

um what -80 lol what

Which is the IUPAC name for NO?
nitric oxide
binitrogen oxide
dinitrogen dioxide
nitrogen monoxide

Answers

The IUPAC name for NO is nitric oxide. The correct option is A.

What is IUPAC naming?

The International Union of Pure and Applied Chemistry (IUPAC) is a global organization that represents chemistry as well as related sciences and technologies.

The chemical compound's identity is represented by its common and IUPAC names, which differ from one another. Every chemical compound has multiple names.

Complete the following step-by-step response: The IUPAC nomenclature is a standardized name given to organic compounds in accordance with official naming rules.

Nitric oxide, also known as NO, is a colorless gas. It is one of the most important nitrogen oxides.

Nitric oxide is a free radical, which means it has an unpaired electron, which is sometimes represented in its chemical formula by a dot.

Thus, the correct option is A.

For more details regarding IUPAC, visit:

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Answer:

D: Nitrogen Monoxide

Explanation:

There's one Nitrogen atom and one Oxygen atom

Which types of matter are made of atoms

a. Mixtures
b. Elements
C. Compounds
D. All of the above

Answers

Answer:

D all above yes I think it's all above

Answer:  D

Explanation: All of the above.

Plz mark brainliest:)

32 N of Force. 37 N force. How strong is the net force and in which direction?

Answers

5 units to the left.

Explanation:
They are working against each other. That means you subtract.

32 - 37 = -5

You are moving 5 units to the left because 37 is negative which means it is moving left. The key word is left. In physics, you would get the same answer if you did it this way.

37 - 32 = 5

The 5 moves in the same direction as the 37


Which RNA strand would match with this DNA strand?
AGGCTAAT

Answers

What is the DNA strand? You have not named it.

ultraviolet radiation has a higher frequency than visible light. which type of light wave carries more energy?
a=they carry the same amount of energy
b=visible light
c= ultraviolet radiation

Answers

Answer:

The answer to this question is C; ultraviolet radiation

Explanation:

The the reason for this is because it carries more energy per photon than visible light does. Light travels at a speed of 299,792 kilometers per second (about 186,282 miles per second).

Name for each compoud
1.CO
2.H2SO4
3CaCO3
4 H202
5NaF

Answers

1. Carbon monoxide
2. Sulfuric acid
3. Calcium carbonate
4. Hydrogen peroxide
5. Sodium fluoride
hope this helps (:

choose the letter that best describes the behavior of a substance during a phase change:

/A/ neither absorbs or releases energy

/B/ always absorbs energy

/C/ always releases energy

/D/ either absorbs or releases energy

Answers

Answer:

/D/ either absorbs or releases energy

Explanation:

During a phase change energy is either absorbed or released.

A phase change is a reversible process which occurs when a substance changes is its state from one form to another.

Phase changes are used to delineate physical changes.

A phase diagram provides a graphic representation of the change. The diagram can be 2 dimensional or 3 dimensional.

Does the use of lithium cause human health problems?

Answers

Answer:

Yes

Explanation:

Lithium can cause nausea, diarrhea, dizziness, change in heart rhythm, muscle weakness, fatigue, and a dazed feeling

Continued use of Lithium could mean fine tremor, frequent urination, and thirst

Source: Webmd.com

Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below. A purple center outlined in black with two concentric black circles around the center, the inner circle having 2 small green balls on it and the outer circle having 8 small green balls on it. What experimental evidence led scientists to change from the previous model to this one? A few of the positive particles aimed at a gold foil seemed to bounce back. The colors of light emitted from heated atoms had very specific energies. Experiments with water vapor showed that elements combine in specific proportions. Cathode rays were bent in the same way whenever a magnet was brought near them.

Answers

Answer:

B: The colors of light emitted from heated atoms had very specific energies.

Explanation:

dont know if its the same question i had on edg but i think its B. Sorry if i didnt understand the question :)

Answer:

b

Explanation:

After lab, all of Darrel's friends looked at his data and laughed and laughed. They told him that he was 30.8% too low in the boiling point he had just recorded. He had recorded a boiling point of 50o C on his data sheet. What is the correct boiling point of the liquid he was working with in lab?

Answers

Answer:

100°

Explanation:

For a boiling point is it always 100°

A dull metal object has a density of 8.8 G/ML and a volume of 20 ML calculate the mass

Answers

Answer:

Mass = 0.000176 gram

Steps:

m =  V × ρ

=  20 milliliter × 8.8 gram/cubic meter

=  2.0E-5 cubic meter × 8.8 gram/cubic meter

=  0.000176 gram

Explanation:

You are about to take a short trip. However, you will not be traveling by car or bus; instead you will be traveling up in a hot air balloon. You know that hot air balloons, like the ones pictured, are able to rise when the air contained in them is heated. Why does the balloon rise? What is happening at the molecular level to make the balloon rise?

Answers

Answer:

Hot air rises. Heated air molecules “spread out” or expand and bounce around, and the space becomes less dense than the surrounding space. Increasing the air temperature inside the balloon envelope makes it less dense than the air, thus making it “lighter than air”.

Explanation:

I'm new to brainly but I hope this helped!

Balloon rise because  Warm air ascends. Heat causes the molecules of the air to "spread out," or expand, and bounce off one another, making the area less dense than the surroundings.

What are molecules ?

A molecule is the smallest unit of a substance that keeps its content and properties. It is made up of two or more atoms that are joined together by chemical bonds.

Chemistry is built on molecules. The element symbol and a subscript indicating the number of atoms are used to identify molecules.

When Balloon rise because  Warm air ascends. Heat causes the molecules of the air to "spread out," or expand, and bounce off one another, making the area less dense than the surroundings.

The air inside the balloon's envelope becomes less dense as the temperature rises, making it "lighter than air."

To learn more about molecules, refer to the below link:

https://brainly.com/question/14130817

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why is lithium used in the body?

Answers

Answer:

11

Explanation:

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