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3 years ago

John Dalton determined that the concept of atoms could be used to describe matter.

Chemistry

2 answers:

astraxan [27]3 years ago

7 0

Answer:

The answer is D

Explanation:

As it is true that molecules are identical in mass.

kramer3 years ago

6 0

Answer:

Explanation:

I don't exactly remember his four points, but the D. is just not true anyway. For example, a molecule of water (H20) does that have the same properties or mass as Nitrogen dioxide or sulfer dioxide or something else

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Zinc sulfate is a 2-ion electrolyte,

Gekata [30.6K]

Answer: The value of i is 1.4 and 40% dissociation of 100 particles of zinc sulfate will yield 60 undissociated particles.

Explanation:

The equation used to calculate the Vant' Hoff factor in dissociation follows:

$\alpha =\frac{i-1}{n-1}$

where,

$\alpha$ = degree of dissociation = 40% = 0.40

i = Vant' Hoff factor

n = number of ions dissociated = 2

Putting values in above equation, we get:

$0.40=\frac{i-1}{2-1}\\\\0.40=i-1\\\\i=1.4$

The equation used to calculate the degee of dissociation follows:

$\alpha =\frac{\text{Number of particles dissociated}}{\text{Total number of particles taken}}$

Total number of particles taken = 100

Degree of dissociation = 40% = 0.40

Putting values in above equation, we get:

$0.40=\frac{\text{Number of particles dissociated}}{100}\\\\\text{Number of particles dissociated}=(0.40\times 100)=40$

This means that 40 particles are dissociated and 60 particles remain undissociated in the solution.

Hence, 40% dissociation of 100 particles of zinc sulfate will yield 60 undissociated particles.

7 0

3 years ago

What is the next step if the data from an investigation do not support the original hypothesis? The hypothesis is revised and an

yanalaym [24]

Answer:

First choice: The hypothesis is revised and another experiment is conducted.

Explanation:

Citing myself from brainly.com/question/12687503, a hypothesis is a reasonable explanation of a phenomenon, which tries to relate a cause with an effect, and that can be testable.

The outcome of the test can either support the hypothesis or reject it.

Both results, either supporting or rejecting the hypothesis, are good for science and help to the development of the scientific knowledge.

Hence, the fact that the data from an experiment do not support the original hypothesis is not a bad thing. The same scientist or other from the scientific community will be able to revise the hypothesis and conduct another experiment, as the first answer choice proposes.

The data are supposed to be correct, unless the analysys, not the conclusion, suggests some errors in the measures or collection of the data. So, it is not the fact that the data do not support the original hypothesis what conducts to run the experiment again (second choice is wrong, then).

The revision of the data to support the hypothesis (third choice) or adjustment of the data to match the observations (fourth hypothesis) are contrary to good practices, so they are also discarded.

5 0

3 years ago

What evidence supports a scientist's conclusion that fossil B is older than fossil A? (4 points)

Hoochie [10]

Answer:

Choice B, as time goes on the surface level rises and stuff buried underground gets further and further below surface level.

3 0

3 years ago

. At 400 K, the half-life for the decomposition of a sample of a gaseous compound initially at 55.5 kPa was 340 s. When the pres

Hitman42 [59]

Answer:

The order of this half-life reaction is zero. This is a zero order reaction.

Explanation:

Step 1: Data given

At the pressure P0,1 of 55.5 kPa, the half-life is 340 s

At the pressure P0,2 of 28.9 kPa, the half-life is 178 s

Step 2: Calculate the order

(n-1) = ((log (t1/2P0,1 / t1/2P0,2)) / (log (P0,2 /P0,1)))

⇒ with t1/2P0,1 = the half-life at a pressure of 55.5 kPa = 340 s

⇒ with t1/2P0,2 = the half-life at a pressure of 28.9 kPa = 178 s

⇒ with P0,1 = the pressure of 55.5 kPa

⇒ with P0,2 = the pressure of 28.9 kPa

(n-1) = (log (340/178)) / log( 28.9/55.5)

(n-1) = log (1.91) / log(0.52)

(n-1) = 0.281 / -0.284

n-1 = -1

n = 0

The order of this half-life reaction is zero. This is a zero order reaction.

4 0

3 years ago

Cytoplasm

gtnhenbr [62]

Answer:

The structure found only in a plant cell is, cell wall

The answer to 19 is b

Explanation:

8 0

3 years ago