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Molodets [167]
3 years ago
9

Humans first appeared in the _____ period.

Chemistry
2 answers:
Ira Lisetskai [31]3 years ago
6 0

Answer:

They first appeared in the fossil record around 66 million years ago, soon after the Cretaceous–Paleogene extinction event that eliminated about three-quarters of plant and animal species on Earth, including most dinosaurs.

Explanation:

vlabodo [156]3 years ago
4 0

Answer:

A or b I learned this in history

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What state of matter has the most kinetic energy
kvv77 [185]

Answer: Gas

Explanation:

since the gas molecules arent being forcefully bonded together like a solid would be, and liquids tend to have lower kinetic energy than solids

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Why are thiols more nucleophilic than alcohols?
Roman55 [17]

Answer:

Thiols contain stronger acids than alcohols

Explanation:

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2 years ago
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Explain the Sun's role in the water cycle
timama [110]
It causes the water to evaporate from the earths surface so that it can cycle through again
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3 years ago
In an aqueous solution of potassium chloride the solute is
Goryan [66]

Answer:

Potassium chloride

Explanation:

A solution is formed by a solvent and one or more solutes.

The solvent is the species that is in major proportion and usually defines the state of aggregation of the solution, while the solute/s is/are in minor proportion.

Also, water is known as the universal solvent, so in any solution containing water, it is considered as the solvent.

Then, in an aqueous solution of potassium chloride the solute is potassium chloride.

7 0
3 years ago
The half-life of radon gas is approximately four days. Four weeks after the introduction of radon into a sealed room, the fracti
maksim [4K]

The fraction of the original amount remaining is closest to 1/128

<h3>Determination of the number of half-lives</h3>
  • Half-life (t½) = 4 days
  • Time (t) = 4 weeks = 4 × 7 = 28 days
  • Number of half-lives (n) =?

n = t / t½

n = 28 / 4

n = 7

<h3>How to determine the amount remaining </h3>
  • Original amount (N₀) = 100 g
  • Number of half-lives (n) = 7
  • Amount remaining (N)=?

N = N₀ / 2ⁿ

N = 100 / 2⁷

N = 0.78125 g

<h3>How to determine the fraction remaining </h3>
  • Original amount (N₀) = 100 g
  • Amount remaining (N)= 0.78125 g
  • Fraction remaining =?

Fraction remaining = N / N₀

Fraction remaining = 0.78125 / 100

Fraction remaining = 1/128

Learn more about half life:

brainly.com/question/26374513

7 0
2 years ago
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