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murzikaleks [220]
3 years ago
15

A fossil is any natural evidence of prehistoric life that provides some idea of the size, shape, or form of the organism. A foss

il does need not to be a whole animal or plant. Broken fragments are also fossils, as are the tracks left behind by the organisms. Fossils provide important evidence of how life and environmental conditions have changed. The fossils found in rock formations of different time periods differ because the environment on Earth has changed.
The various kinds of animals and plants that once lived in Pennsylvania provides evidence of the environmental changes of early Pennsylvania from the ___________________________.
A) very good record keeping
B) plants preserved as fossils
C) animals preserved as fossils
D) plant and animals preserved as fossils
Chemistry
2 answers:
Levart [38]3 years ago
6 0
I believe it’s C or D
yulyashka [42]3 years ago
6 0

geez the answer is D. its not C or D


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What is Q= mc delta t
Mariulka [41]

Answer:

Explanation:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

The substances with higher value of specific heat capacity require more heat to raise the temperature by one degree as compared the substances having low value of specific heat capacity.For example,

The specific heat capacity of oil is 1.57 j/g. K and for water is 4.18 j/g.K. So, water take a time to increase its temperature by one degree by absorbing more heat while oil will heat up faster by absorbing less amount of heat.

Consider that both oil and water have same mass of 5g and change in temperature is 15 K. Thus amount of heat thy absorbed to raise the temperature is,

For oil:

Q = m.c. ΔT

Q = 5 g× 1.67 j/g K × 15 K

Q = 125.25 j

For water:

Q = m.c. ΔT

Q = 5 g× 4.18 j/g K × 15 K

Q = 313.5 j

we can observe that water require more heat which is 313.5 j to increase its temperature.

6 0
3 years ago
You have a 1.8 M solution of HCI. You need to make a 0.70 M solution with a volume of 550 mL. How many mL of the stock solution
Arte-miy333 [17]

The volume of the stock solution needed is 213.88 mL to get new concentration.

<h3>What is molarity?</h3>

Molarity (M) is the amount of a substance in a certain volume of solution. Molarity is defined as the moles of a solute per litres of a solution.

Determination of the volume of stock solution.

Volume of diluted solution (V₂) =550 mL

Molarity of diluted solution (M₂) =0.70 M

Molarity of stock solution (M₁) = 1.8 M

Volume of stock solution needed (V₁) =?

M₁V₁ = M₂V₂

1.8 M  × V₁ = 0.70 M × 550 mL

V₁ = 213.88 mL

Thus, the volume of the stock solution needed is 213.88 mL.

Learn more about the molarity here:

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5 0
1 year ago
n‑methyl‑2‑pyrrolidone is an aprotic solvent used in many industrial processes. draw the structure of the product formed when it
kotegsom [21]

The structure of n‑methyl‑2‑pyrrolidone when it is heated with aqueous acid. product is given below

<h3 /><h3>What is  aprotic solvent?</h3>

A polar solvent without an acidic proton is known as a polar aprotic solvent. These solvents don't include hydroxyl or amine groups. These solvents can act as proton acceptors, but unlike protic solvents, they do not act as proton donors in hydrogen bonding.

After being exposed to a strong aqueous acidic media and being heated, N-methyl-2-pyrrolidone opens up, forming a molecule with a carboxylic group at one end and a protonated nitrogen atom with a methyl group connected to it at the other.

Alcohol, water, hydrogen fluoride, formic acid, acetic acid, ammonia, methanol, ethanol, and other well-known substances are a few examples of polar protic solvents. Polar aprotic solvents, on the other hand, lack acidic protons and do not function as donors during hydrogen bonding.

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7 0
1 year ago
Which two options are examples of waves refecting
sergey [27]

Answer:

A voice echo

Your image in a mirror

Explanation:

hope this helps

8 0
2 years ago
What is the speed of a car that traveled 40.2km in 2 hours?
PolarNik [594]

Answer:

20 km per hour

Explanation:

7 0
2 years ago
Read 2 more answers
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