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

What is hydrochloride acid plus water plus salt and water

Answers

ANSWER:

It is called Caffeine Hydrochloride.
Formula: HC8H10N4O2Cl

Convert 122 moles of Methane to liters?

Answers

122 moles of Methane to liters is 2734.5

What is the mass obtained of Ag from the reaction of 3 moles of AgCl

Given= Zn + 2AgCl —> ZnCl2 + 2Ag

Answers

Answer:

323.7g

Explanation:

Given parameters:

Number of moles of AgCl = 3 moles

Unknown:

Mass of Ag = ?

Solution:

We solve this problem by working from the known to the unknown;

The known here is AgCl;

    From the balanced equation:

              Zn + 2AgCl → ZnCl₂ + 2Ag    

              2 moles of AgCl will produce 2 moles of Ag

              3 moles of AgCl will produce 3 moles of Ag

The mass of Ag will be;

     Mass of Ag  = number of moles x molar mass

Molar mass of Ag = 107.9g/mol

      Mass of Ag = 3 x 107.9  = 323.7g

why people on earth cannot see the entire shape of the milky way

Answers

Answer:

Explanation:

That is because the Milkyway is full of dust and gas, you cannot really see something if it has dust and gas

Answer:

Its too far away to see

Explanation:

You would probably have to be in space

1. Calculate the average atomic mass of iron if its abundance in nature is 15%-iron-55 and
85% iron-56

Answers

The average atomic mass of iron : 55.85 amu

Further explanation

The elements in nature have several types of isotopes

Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.

An atomic mass unit = amu is a relative atomic mass of 1/12 the mass of an atom of carbon-12.

The 'amu' unit has now been replaced with a unit of 'u' only

Atomic mass is the average atomic mass of all its isotopes

atomic mass X = mass isotope 1 . % + mass isotope 2.% ...

The average atomic mass of iron

[tex]\tt =0.15\times 55+0.85\times 56\\\\=\boxed{\bold{55.85~amu}}[/tex]

The average atomic mass of iron : 55.85 amu

Calculation for average atomic mass:

Isotopes are atoms whose atoms have the same number of protons while still having a different number of neutrons.

An atomic mass unit = amu is a relative atomic mass of 1/12 the mass of an atom of carbon-12.

The 'amu' unit has now been replaced with a unit of 'u' only

Atomic mass is the average atomic mass of all its isotopes.

Atomic mass X = mass isotope 1 *  Mas % + mass isotope 2* Mass %

The average atomic mass of iron:

=0.15 * 55 + 0.85 * 56

=55.85 amu

Thus, the average atomic mass of iron : 55.85 amu

Find more information about Average atomic mass here:

brainly.com/question/338808

A student states that photosynthesis is conducted only in plant cells and that cellular respiration occurs only in animal cells. Tell whether the student is correct and why. In your response, be sure to describe both processes and the structures involved. Upload your answer below.

Answers

Answer:

This is correct

Explanation:

This is correct because for photosynthesis you need organelles such as chloroplasts, chloroplasts absorb light energy and convert it into usable energy for plants. Animal cells do not have chloroplasts/similar organelles so  they can't absorb energy from the sun, Animal cells use mitochondria which takes energy from our food and breaks it down into usable energy(such as ATP) to be transported.

A mixture is made of two or more materials that
A. can be separated by physical means.
В.
cannot be separated by physical means.
C.
cannot be separated by any means.
D
can only be separated by chemical means.

Answers

Answer:

A. can be separated by physical means.

Explanation:

A mixture is when two different materials are put in the same container and no reaction occurs.

Which description applies to a physical property? Choose the correct answer
O depends directly on the amount of the substance present
O examines changes in the composition and structure of matter
O measured or observed without changing the identity and composition of matter
O determined by changing the identity of a substance and observing how it reacts

Answers

Answer:

the third one, measured or observed without changing the identity and composition of matter. because physical property does not under go any change but can be put back.

A student compared some chemical and physical properties of three pure substances. Her
data are recorded in the chart above. What is a logical conclusion the student can draw
about hare substances?
Pure substances have the same chemical and physical properties.
Pure substances have the same chemical properties, but different physical properties.
O Pure substances have the different chemical properties, but the same physical properties.
O Pure substances have different chemical and physical properties.

Answers

Answer:

letter b not c

Explanation:

next time please take a picture lucky i already took this

i dont get what it means by of touch

Answers

Answer:

So I don't know what do you mean by that, please be a little specific.

Explanation:

^^

Gamma
ray
Which has the longest wavelength?
Ultra-
violet Infrared
Radio
Which has the highest frequency?
X-rays Visible
Microwave
WWW

Answers

Answer:

Radio waves

X-rays Visible

Explanation:

The wavelength of a wave is the difference between successive crests on a wave line. Waves with a very high wavelength have low energy.

Frequency is the number of waves that pass a point per unit of time. The higher the frequency, the higher a wave's energy.

From the given spectrum, wavelength increases from left to right. This puts radio waves as the wave with the longest wavelength. It is also right to say, it has the least energy. Also, frequency decrease from left to right. Gamma rays have the highest frequency in the spectrum. This is followed by x-rays.

Answer:

Radio waves

X-rays Visible

Explanation:

Which of the following is NOT an example of a chemical change? *
O Corrosion
O Grinding
O Combustion
O Rust

Answers

Grinding as it’s a physical not chemical change :)

Find an element that has the same
number of valence electrons as
Thallium (T1).
i need the answer nowww

Answers

Answer:sodium

Explanation: because its not hard to look on the PERIODIC TABLE


Scott and James work at a grocery store. After the grocery
store closed, they were playing a game with a shopping cart
and Scott's skateboard. They crashed the skateboard and
the shopping cart two times. The shopping cart had more non

Answers

Answer: b) Crash 2; the force on the cart was stronger in this crash, so the force on the skateboard was also stronger.

Explanation:

1. Matter that is composed of two or more different
elements chemically combined in a fixed proportion
is classified as
A) a compound
C) a mixture
B) an isotope
D) a solution

Answers

It’s A: a compound I hope u doing well on ur hw

how can prey benefit from the predator having a disease?

Answers

The disease can slow the predator down and the prey can get away easily.

What is the most common isotope of lithium?

Answers

Lithium-7 is the most common isotope of lithium.

The
force acting on an object is the combination of
all of the individual forces acting on it.
Check it
2 SCRATCHPAD
~ Improve this questio

Answers

Answer:

Yes as you can improve The invisible to human eye force or physical force if any being applied to a object of any mass and with all individual forces as they are acting on this object

Explanation:

How did Thomson's experiment change Dalton's atomic model?
A. Thomson discovered that atoms changed properties when put in
an electric field.
B. Thomson discovered that atoms did not rearrange when forming
compounds.
C. Thomson discovered that atoms of one kind of element could
have different masses.
D. Thomson discovered that the atom contained smaller particles
called electrons.

Answers

Answer:

D. thomson discovered that the atom contains smaller particles called electrons

Thomson discovered that the atom contained smaller particles called electrons. The correct option is D.

What is Dalton's atomic model?

Dalton proposed that all matter is composed of tiny indivisible particles known as atoms, which he envisioned as "solid, massy, hard, impenetrable, movable particle(s)."

Thomson's experiment altered Dalton's atomic model by revealing the existence of smaller particles known as electrons within the atom.

The first part of his theory states that all matter is made up of indivisible atoms. According to the second part of the theory, all atoms of a given element have the same mass and properties.

One of Dalton's most important contributions is that it does not violate several fundamental laws of chemical combination, including the law of definite proportions, the law of multiple proportions, and the law of conservation of mass.

Thus, the correct option is D.

For more details regarding Dalton's atomic model, visit:

https://brainly.com/question/12766754

#SPJ2

compound name of SO2

Answers

The compound name is SO2 is Sulfur dioxide. I hope this helps!!

What is the purpose of the title of a line graph

Answers

Answer:

It tells about the data for each line graph is plotted.

Explanation:

Answer:

It can describe what the line graph is measuring and how it is measuring it

Which of the following wave types must have a medium to travel?
A. Ultraviolet light
B. Microwaves
C. Seismic (earthquake) waves
D. Radio waves
E. X rays

Answers

Answer:

it is B

Explanation:

Answer: B microwaves

Help ASAP plzzzz!!!!!!!!

Answers

Answer:

Granite Solid

Milk Liquid

Neon is gas

Wood Is solid

Paper is solid

Helium is Gas

Water is liquid

Air is Gas

Alcohol is liquid

Metal is solid

Nitrogen is gas

Juice is liquid

Oil is liquid

Water Vapor is Gas

Brick is Solid

Propane is Gas

Fabric is solid

Gasoline is Liquid

Explanation:

Hope Dis helped :D :3

I agree with the person above, me you can search those up or look on the periodic table for some of them because metals are to the left and non-metals are to the right.

true or false there is a risk of explosion in factories handling powders such as custard powder

Answers

Answer:

True? I think so At least

Explanation:

Brainliest please helppppppppp

Answers

Ayour anwerser

Explanation

Answer:

chlorine manoxside

co2

Explanation:

The first column of the periodic table is called the

Answers

alkali metals
if i’m correct pls mark me brainliest <3

where is lithium used in the body?

Answers

Answer:

u

Explanation:

A student combines two clear liquid chemicals together in a beaker. When the two chemicals are combined, bubbles are formed, the solution turns blue, and you can see flakes of something forming on the bottom of the beaker. Is this a physical or chemical change? Why?

Answers

Answer:

chemical change

Explanation:

A physical change is one that makes changes to the physical properties of matter. In many cases, the difference is usually reversible. Examples include boiling, melting, freezing, the magnetization of metals, etc.

A chemical change is one in which a new kind of matter is formed. It is usually accompanied by energy changes, i.e., the evolution or absorption of energy in the form of heat or light. This process is not easily reversible. Examples include; combustion, rusting of iron, precipitation, the souring of milk, etc.

From the question given, the combination of two clear liquid in a beaker which results to formation of bubbles and changes in coloration of the solution is a chemical change.

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:)

How did John Newlands order the elements?

Answers

Hello friend! Hopefully this helps you as much as needed!

An English scientist called John Newlands put forward his Law of Octaves in 1864. He arranged all the elements known at the time into a table in order of relative atomic mass. He then put the similar elements into vertical columns, known as groups.

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