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Greeley [361]
3 years ago
13

A geologist studies layered rock to determine its age. Bacteria fossils from the Precambrian age are found in the rock’s upper l

ayers, but no fossils are found in the rock’s bottom layer. Which of these conclusions about the rock is bet supported by evidence?
Chemistry
1 answer:
kondor19780726 [428]3 years ago
4 0
Answer:
The bottom layers of the rock could have formed before life occurred.

Explanation:
The bottom layers of the rock could have formed before life occurred because there is no fossil is present. If there is life at that time so the fossils are present at the bottom layer so the absence indicates that is no life present at that time. The bottom layer is older than the upper layer so that's why fossils of bacteria are found in the upper layer of the rock.

Answer:
C. Because bacterial fossils are found only in the upper layers, scientists can conclude that these bacteria evolved towards the end of Precambrian time.

There’s two different types of answers for this question so I just put both of them. Hope it helps : )

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a solution must be at a higher temperature than a pure solvent to boil. what colligative property can be employed to achieve thi
Kazeer [188]

Boiling-point elavation.

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3 years ago
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This planet is about the size of Earth. It has a very thick atmosphere with
emmainna [20.7K]

Answer:

Venus

Explanation:

Mars has a thin atmosphere

Saturn is really cold (-288F)

Mercury has no atmosphere

4 0
3 years ago
Give the quantum number set for one electron in the 3p sub level of a sulfur (S)
vesna_86 [32]

Answer:- Atomic number for sulfur is 16 and it's electron configuration is 1s^2 2s^2 2p^6 3s^2 3p^4. Here, there are total for electrons in 3p and the set of quantum numbers for these 4 electrons would be as..

For the first electron of 3p-

n = 3, l = 1, ml = -1 and ms = +(1/2)

for the second electron of 3p-

n = 3, l = 1, ml = 0 and ms = +(1/2)

for the third electron of 3p-

n = 3, l = 1, ml = +1 and ms = +(1/2)

and for the fourth electron of 3p-

n = 3, l = 1, ml = -1 and ms = -(1/2)

3 0
3 years ago
In a two-step synthesis, C6H11Br is converted into C6H12O. From the structure of the product, molecular formula of the starting
tamaranim1 [39]

Answer:

See explanation below

Explanation:

The question is incomplete. However in picture 1, you have the starting materials and the structure of the product, which you miss in this part.

Now, in picture 2, you have the starting reactant and the product, and the mechanism that is taking place here.

First, all what we have here is an acid  base reaction. In the first step, we are using the acid medium to convert the reactant into an alcohol. The bromine there, is not leaving the molecule yet, because it's neccesary for the next step. The starting reactant is an alkene, in that way, we can convert the reactant in the first step into a secondary alcohol. In other words, the first reaction is a alkene hydration.

In the second step, we use a strong base. You may say this is a strong nucleophile and will do a Sn2 reaction to form another alcohol there, but it's not the case, because, before any kind of reaction happens, the priority here is always the acid base, so the base will react with the acidic hydrogen. In this case, it will substract an hydrogen from the OH. When this happens, the lone pair will do an auto condensation here, and attacks the bromine in the molecule. In this way, the molecule will become a cyclomolecule, and that way it form the final product.

See picture 2, for mechanism

8 0
3 years ago
Hydration of alkynes gives good yields of single compounds only with symmetrical or terminal alkynes. Draw the major organic pro
Alexxandr [17]

Answer:

Following are the solution to the given choice:

Explanation:

Hex-2-yne is just not alkyne symmetric, therefore two things respectively hexan-3-one and hexan-2-one are to be given.

The attached file it displayed the response along with the mechanism, please find the.

8 0
3 years ago
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