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Which scientist most likely studied tadpole cells under a microscope? a.SchwannB.JanssenC.HookeD.Schleiden

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Which scientist most likely studied tadpole cells under a microscope? a.SchwannB.JanssenC.HookeD.Schleiden

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A scientist needs to know the temperature of the water every 5 m along 3 km of the river. What tool would the scientist use?

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A scientist needs to know the temperature of the water every 5 m along 3 km of the river. What tool would the scientist use?

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Identify the scientist that discovered the theory of evolution

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Identify the scientist that discovered the theory of evolution

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During an experiment on frog embryos,a scientist removes a few cells from the neural tube. What effect would this have on the embryo

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During an experiment on frog embryos,a scientist removes a few cells from the neural tube. What effect would this have on the embryo

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Creativity helps a scientist toA) propose non testable theories about solar system B)post valid scientific questions about solar systemsC) give unacceptable explanations about the solar systemD) use biased methods to answer questions about the solar system

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Answer:

1) Water has very high specific heat.

2) It expands when it freezes

3) ability to dissolve in ionic substances

4) Water molecules at the surface experience fewer hydrogen bonds than water molecules within the liquid.

Explanation:

1) Water molecules due to their high specific heat , undergo relatively less increase in temperature after absorbing heat. So they prevent their adjoining area to experience sharp increase in temperature.

2) Water is an example which expands on freezing. In it , large spaces are left between molecules when it cools. It happens because hydrogen bonds prevent any two molecules to come very close thereby  creating gaps. This gap is filled up when ice melts , which results in overall reduction in volume of water.

3) Uneven distribution of charge results in water molecules becoming polar in nature . A polar substance  can be dissolved in polar solvents only.

4) It is due to property of surface tension. Property  of surface tension results due to molecules of water near the surface experiencing a  net downward  force due to hydrogen bonds . It is due to fewer hydrogen bonds made by them.

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In order to test a hypothesis, the variable that the scientist changes to a predetermined value is known as _________________. is. the controlled variable b. the dependent variable c. the independent variable d. all of the above

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Keywords:

Polynomial, identify, ascending order

For this case, we must identify the polynomial that is written in ascending order. If we want to order a polynomial of ascending form, we must organize the polynomial from least to greatest exponent. By definition, a polynomial is of the form:

P (x) = ax ^ n + bx ^ {n-1} + ... + cx ^ 3 + dx ^ 2 + ex + f

Where:

a, b, c, d, e, f: They are the coefficients of the polynomial

n, n-1,3,2,1,0: They are the exponents. This polynomial is of degree “n”, because “n” is the largest exponent.

x: It is the variable

Then, we must see among the options given a polynomial written from least to greatest exponent, that is, from the form:

P (x) = f + ex + dx ^ 2 + cx ^ 3 + ... + bx ^ {n-1} + ax ^ n

So, among the options we have:

Q (x) = - 7 + 4x-5x ^ 2 + 3x ^ 3 written ascending

Answer:

Option C

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An oceanographer discovered new seafloor being formed in the ocean at a divergent fault. The scientist classifies this as a trench. Is the scientist correct or incorrect and why or why not?

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The scientist is incorrect in his statement.

The new seafloor is formed at places where there’s divergent plate boundaries. Because the two or more plates are moving away from one another, the crust becomes thinner, so the high temperatures, pressures, and magma manage to penetrate from the mantle very easily. The magma that comes out on the surface is cooling off very quickly and is creating igneous rocks, thus new crust, or new seafloor if you will.

The trenches are appearing at places of convergent plate boundaries, and they are not places where new seafloor is formed, but rather places where one tectonic plate submerges under another tectonic plate.

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A scientist adds heat to each of the following substances. Which will probably absorb the most heat before its temperature changes significantly? 50 g of solid copper 50 g of solid iron 50 g of liquid water 50 g of sand Question 2(Multiple Choice Worth 2 points) A drop of water placed on a smooth, dry surface will form a dome-shaped droplet instead of flowing outward in different directions. Which of these best explains this observation? The bonds between hydrogen and oxygen atoms are very strong. The electrons in the atoms attract the electrons in the other atoms. Water molecules at the surface experience fewer hydrogen bonds than water molecules within the liquid. Water molecules near the surface produce more buoyant force than water molecules within the liquid. Question 3(Multiple Choice Worth 2 points) Which of these best explains what happens when the ionic substance calcium chloride (CaCl2) dissolves in water? The oxygen atoms in the water molecules are attracted to the Ca2+ ions. The oxygen atoms in the water molecules are attracted to the Cl− ions. The hydrogen atoms in the water molecules are attracted to the Ca2+ ions. The oxygen atoms in the water molecules are attracted to the H+ ions. Question 4(Multiple Choice Worth 2 points) Which of these statements about water is true? Its atoms share electrons equally. It can dissolve all known substances. Its molecules are farther apart in the solid state than in the liquid state. It has a lower specific heat than nearly all known metals.

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The gravitational force Fg between two objects is given by the equation:

Fg=(G*m₁*m₂)/r₂, where G=6.67*10^-11 m³ kg⁻¹ s⁻² is the gravitational constant, m₁ and m₂ are the masses of the two bodies and r is the distance between those bodies. 

Due to the gravitational attraction the pencil and the eraser will attract if we there is no friction on the surface. 

m₁=10 g=0.01 kg is the mass of the pencil
m₂=20 g=0.02 kg is the mass of the eraser
r=2.5 cm = 0.025 m

First we calculate the Fg:

Fg={(6.67*10^-11)*0.01*0.02}/(0.025²)=2.1344*10^-11 N

To get the velocity v of the pencil:

v²=2as, where a is the acceleration of the pencil and s is the path. In our case s=r so we can write:

v²=2ar

a=Fg/m₁= 2.133*10^-9 m/s²

v²=2*(2.133*10^-9)*0.025=1.0665*10^-10

v=√(1.0665*10^-10)=1.0327*10^-5 m/s

We have the velocity and the acceleration, so we can calculate the time t with the equation:

t=v/a=(1.0327*10^-5)/(2.133*10^-9)=4841.6 s

1 hour has 3600 s so when we divide time t in seconds by 3600 we get time T in hours:

T=t/3600=4841.6/3600=1.3449 h. 

So the time for the pencil and eraser to touch is T=1.3449 hours. 

Also time T can be expressed like T= 1h and 20 mins and 41.64 s

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Areas near oceans or large lakes tend to have more moderate climates than do areas far from large bodies of water. Which of these statements best explains this observation? Hydrogen and oxygen atoms share electrons in a water molecule. Lakes and oceans contain dissolved solids. Water has a very high specific heat. Water produces buoyant forces. Question 2(Multiple Choice Worth 2 points) A scientist discovers a new substance. The molecules of the substance form hydrogen bonds with each other. When the molecules lose a lot of energy, the hydrogen bonds hold them relatively far apart. Based on this information, what can the scientist infer about the substance? It expands when it freezes. It is highly colored. It exists only as a gas. It does not dissolve ionic compounds. Question 3(Multiple Choice Worth 2 points) Which of the following properties of water is due primarily to the uneven distribution of charge between the hydrogen and oxygen atoms? its color its taste its ability to dissolve ionic substances its ability to produce buoyant forces Question 4(Multiple Choice Worth 2 points) A drop of water placed on a smooth, dry surface will form a dome-shaped droplet instead of flowing outward in different directions. Which of these best explains this observation? The bonds between hydrogen and oxygen atoms are very strong. The electrons in the atoms attract the electrons in the other atoms. Water molecules at the surface experience fewer hydrogen bonds than water molecules within the liquid. Water molecules near the surface produce more buoyant force than water molecules within the liquid.

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The gravitational force Fg between two objects is given by the equation:

Fg=(G*m₁*m₂)/r₂, where G=6.67*10^-11 m³ kg⁻¹ s⁻² is the gravitational constant, m₁ and m₂ are the masses of the two bodies and r is the distance between those bodies. 

Due to the gravitational attraction the pencil and the eraser will attract if we there is no friction on the surface. 

m₁=10 g=0.01 kg is the mass of the pencil
m₂=20 g=0.02 kg is the mass of the eraser
r=2.5 cm = 0.025 m

First we calculate the Fg:

Fg={(6.67*10^-11)*0.01*0.02}/(0.025²)=2.1344*10^-11 N

To get the velocity v of the pencil:

v²=2as, where a is the acceleration of the pencil and s is the path. In our case s=r so we can write:

v²=2ar

a=Fg/m₁= 2.133*10^-9 m/s²

v²=2*(2.133*10^-9)*0.025=1.0665*10^-10

v=√(1.0665*10^-10)=1.0327*10^-5 m/s

We have the velocity and the acceleration, so we can calculate the time t with the equation:

t=v/a=(1.0327*10^-5)/(2.133*10^-9)=4841.6 s

1 hour has 3600 s so when we divide time t in seconds by 3600 we get time T in hours:

T=t/3600=4841.6/3600=1.3449 h. 

So the time for the pencil and eraser to touch is T=1.3449 hours. 

Also time T can be expressed like T= 1h and 20 mins and 41.64 s

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QUESTION 4 A scientist who alters data to ensure a desired outcome is: Behaving unethically Displaying creativity Proving a hypothesis correct QUESTION 5 An ethical scientist exhibits which of the following characteristics? Bias Logic Honesty QUESTION 6 Scientists who work with human subjects have an ethical responsibility to ensure their subjects are not harmed. True False QUESTION 7 Scientists must report data honestly, regardless of personal bias. True False 2 points Save Answer QUESTION 8 A scientist only reports data that supports his hypothesis that a new medication has a positive outcome for certain patients. This is an example of which of the following? A hypothesis Bias Logic 3 points Save Answer QUESTION 9 Scientists may disregard data that conflicts with their personal preferences. True False

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The equation of the car is given by the equation,

                          x(t) = 2.31 + 4.90t² – 0.10t⁶

If we are going to differentiate the equation in terms of x, we get the value for velocity.

                  dx/dt = 9.8t – 0.6t⁵

Calculate for the value of t when dx/dt = 0.

                 dx/dt = 0 = (9.8 – 0.6t⁴)(t)

The values of t from the equation is approximately equal to 0 and 2. 

If we substitute these values to the equation for displacement,

(0)   , x = 2.31 + 4.90(0²) – 0.1(0⁶) = 2.31

(2)    , x = 2.31 + 4.90(2²) – 0.1(2⁶) = 15.51

Thus, the positions at the instants where velocity is zero are 2.31 and 15.51 meters. 

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"Life as we know it is impossible without water." Explain why a scientist might make this statement. Give two examples to support your answer.

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“Life as we know it is impossible without water.” Explain why a scientist might make this statement. Give two examples to support your answer.

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Adenine,guanine,cytosyne and thymine are the four nitrogenous bases present in the DNA of all organisms.Which scientist discored these bases?

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Adenine,guanine,cytosyne and thymine are the four nitrogenous bases present in the DNA of all organisms.Which scientist discored these bases?

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When working on a project a scientist discovers that some of the data she was basing her research on was not accurate. what should the scientist do?

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There came other atom models: Thompson’s
model, Rutherford’s model, Bohr’s model… and finally, Schrödinger’s theory.

Besides, keep
in mind that:

-When an atom
loses an electron, that electron has to end up in another atom, and then you
have cations and anions… and a cation always has to be near an anion… so they
are sort of keeping an eye on their missing electrons.
-The only situation
where we find isolated neutrons is during nuclear reactions… and remember those
are dangerous chain reactions! The atomic bomb is an example of that.
-We can have
isolated protons and we call them H+ – so it works as any other cation. You can
find H+ in water, where we also have OH-.

Let’s talk
about Thompson’s model: They call it the “plum pudding”. It consisted on a large positive charge (the pudding) filled
with little negative charges (the plums).

And this is Rutherford’s
model: He found out negative charges (electrons) were actually spinning around
the positive nucleus. But he didn’t say anything about the shapes or sizes of
their orbits.

Then you have
the Bohr’s model, also known as the planetary model. Bohr said that there are
smaller orbits, closer to the nucleus, and larger orbits, in the outer part of
the atom, and did propose a lot of detail about the orbits. But it still wasn’t
enough accurate.

Schrödinger’s
focused on finding more details about where in the atom you can find each
electron, its velocity, its momentum, etc.

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What scientist shot alpha particles into gold

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Answer:

A change in which chemical composition of the substance changes is known as a chemical change and said to have undergone a chemical reaction and a change in which only the physical properties of a substance change is known as a physical change.

Processes like cutting, grinding, phase change (melting, freezing, boiling) are all physical changes.

Processes like corrosion, burning are chemical changes.

Physical change:

A seed into seedling

wax melting from applied heat

grinding wheat to make flour

adding copper with gold to make jewelry

In all of the above examples, only the physical properties such as size, shape and phase has changed. hence, these are physical changes.

Chemical reaction occurs in:

making caramel by  burning sugar

tarnishing of silver

A chemically different new product is being formed when substance undergoes a chemical reaction like in the above examples.

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A scientist counts 25 bacteria present in a culture and finds that the number of bacteria triples each hour. The function y = 25 ∙ 3x models the number of bacteria after x hours. Estimate when there will be about 1170 bacteria in the culture

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A scientist counts 25 bacteria present in a culture and finds that the number of bacteria triples each hour. The function y = 25 ∙ 3x models the number of bacteria after x hours. Estimate when there will be about 1170 bacteria in the culture

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While looking at a cell under a microscope, a scientist is able to see a biological molecule. This molecule is a nucleic acid with double strands and contains the nitrogenous bases adenine, thymine, cytosine, and guanine. Based on this information, what conclusion can the scientist draw regarding this nucleic acid

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While looking at a cell under a microscope, a scientist is able to see a biological molecule. This molecule is a nucleic acid with double strands and contains the nitrogenous bases adenine, thymine, cytosine, and guanine. Based on this information, what conclusion can the scientist draw regarding this nucleic acid

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NEED HELP ASAP!!!!!!!!!!!!!!!!!!!!!!!!!!!!! A scientist measures the rate of a reaction between two liquids. Then he performs the reaction again, adding solid manganese. The reaction takes place more quickly the second time. The mass of the manganese decreased by 0.45 grams during the reaction. He claims that the manganese acted as a catalyst because it sped up the reaction. Explain what is wrong with the scientists’ reasoning.

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       Density = (mass) / (volume)

                                4,000 kg/m³ = (mass) / (0.09 m³)

Multiply each side
by  0.09 m³ :           (4,000 kg/m³) x (0.09 m³) = mass

                                 mass = 360 kg .

Force of gravity = (mass) x (acceleration of gravity)

                           = (360 kg) x (9.8 m/s²)

                           = (360 x 9.8)  kg-m/s²

                           =   3,528 newtons .  

That’s the force of gravity on this block, and it doesn’t matter 
what else is around it.  It could be in a box on the shelf or at 
the bottom of a swimming pool . . . it’s weight is 3,528 newtons 
(about 793.7 pounds). 

Now, it won’t seem that heavy when it’s in the water, because 
there’s another force acting on it in the upward direction, against 
gravity.  That’s the buoyant force due to the displaced water.

The block is displacing 0.09 m³ of water.  Water has 1,000 kg of 
mass in a m³, so the block displaces 90 kg of water.  The weight 
of that water is  (90) x (9.8) = 882 newtons (about 198.4 pounds), 
and that force tries to hold the block up, against gravity.

So while it’s in the water, the block seems to weigh

       (3,528  –  882) = 2,646 newtons  (about 595.2 pounds) . 

But again … it’s not correct to call that the “force of gravity acting 
on the block in water”.  The force of gravity doesn’t change, but 
there’s another force, working against gravity, in the water.

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Suppose a scientist doing an experiment in nuclear fusion starts out with twelve atoms. How many atoms will most likely result from the experiment?

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Explanation :

The forces that govern all matter in the universe are :

(1) Gravitational force

(2) Electromagnetic force

(3) Strong nuclear force

(4) Weak nuclear force

The characteristics of the weak nuclear force are:

(1) These forces are stronger than gravity.

(2) These forces are effective only for short distances i.e. has a very small range.

(3) These forces are weaker than the electromagnetic force because electromagnetic force is about 10^{11} times that of weak nuclear force.

(4) These forces are responsible for radioactive decays. So, these forces are repulsive.

So, final answer is :

is repulsive, has a very small range, is stronger than the gravitational force

and is weaker than the electromagnetic force.

Hence, this is the required solution.

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After the last major ice age, sea levels around the world rose. As they did, the rising waters divided what was once a single island in the North Sea into two different islands. A population of rabbits was split between the two islands. Ten thousand years passed with no contact between the two rabbit groups. In recent times, a scientist attempted to breed individuals from the two groups, but he was unsuccessful in doing so. Why were rabbits from the two groups unable to produce offspring together? A.The groups belonged to different breeds of rabbits. B.The groups were adapted to very different climates. C.The groups had evolved into separate species. D.The groups were not able to recognize each other.

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a. (+4, -2)

We can use the following conventions:

– x-axis: east-west direction, with east being positive x and west being negative x

– y-axis: north-south direction, with north being positive y and south being negative y

With this coordinates, the movie theater is:

– 4 km east –> this means x = +4

– 2 km south –> this means y = -2

So, the coordinates of the theater are (+4,-2)

b. (-1,+1)

We drive 5 km west (which means Delta x = -5) and 3 km north (which means Delta y = +3). We have to add these displacements to each coordinate. we find:

x'= x_0 + Delta x = +4 + (-5) = -1\y' = y_0 + Delta y = -2 + (+3)=+1

So, the coordinates of the restaurant are (-1, +1)

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) A scientist who is researching marshes observes that marsh grass, Spartina bakeri, grows to different heights at different locations in the marsh. If the scientist wants to find the reason for this difference, what is the correct first step?

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Answer: Hello there!

we have the equation y = 1.09x, that describes the number of yards y in x meters.

a) Yes, if you have negative numbers of x (this means negative meters, this is used usually to denothe something that is behind the observer) then the equation transform them into negative yards.

b) in this case you want to know how many meters are in 40yd, then we replace y by 40yd in the equation:

40 = 1.09x

x = 40/1.09 = 36.7 meters

so in a 40yd race, there are 36.7 meters.

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