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3 years ago

1. What is the geologic time scale? Explain how the geologic time scale is a model.

Chemistry

2 answers:

oksano4ka [1.4K]3 years ago

6 0

This is the answer hope it will help you

tiny-mole [99]3 years ago

5 0

1.) the geologic time scale is a system of chronological dating that relates geologic structure to geologic events. it is a model because it measures and describes events and relationships in geologic history.

2.) the paleozoic period was roughly from 245 million years ago to 545 million years ago.

3.) the dinosaurs lived in the mesozoic era, specifically the triassic period, which was roughly around 230 million years ago.

4.) the first early human relatives were found roughly around d the neogene period, about 25 million years ago, and is in the cenozoic era.

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Which element is used for the shiny trim on cars

galben [10]

<span>The correct answer is either Chrome (Chromium), or Aluminum. Unlike steel, these two don't rust easily and can be polished to be quite shiny, especially Chromium, which is why you'll always hear people who like cars talking about chrome wheels and chrome spoilers and things like that. They are not that good for bumpy or roads that are full of holes because they can bend much easier than steel so it can be expensive to maintain.</span>

7 0

4 years ago

Write the balanced NET IONIC equation for the reaction that occurs when ammonium nitrate and potassium hydroxide are combined. N

vova2212 [387]

Answer:

Net Ionic equation

NH₄⁺ + OH⁻ → NH₃ + H₂O

Option B is correct.

Weak Acid Strong Base

Check Explanation for the extent of the reaction.

Explanation:

Ammonium nitrate = NH₄NO₃

Potassium Hydroxide = KOH

Ammonium salts combine with alkalis to liberate NH₃ and form water.

The two reactants combine to give

NH₄NO₃ + KOH → KNO₃ + NH₃ + H₂O

In ionic form,

- NH₄NO₃ exists as NH₄⁺ and NO₃⁻

- KOH exists as K⁺ and OH⁻

- KNO₃ as K⁺ and NO₃⁻

And NH₃ and H₂O stay as they are, as per covalent compounds.

So, we have

NH₄⁺ + NO₃⁻ + K⁺ + OH⁻ → K⁺ + NO₃⁻ + NH₃ + H₂O

Eliminating the ions that exist on both sides, we have the net ionic equation to be

NH₄⁺ + OH⁻ → NH₃ + H₂O

which shows that this reaction is essentially a neutralization reaction in which the Bronsted Lowry acid, NH₄⁺, loses its proton to the base, OH⁻ and gives conjugate base, NH₃ and conjugate acid, H₂O.

This reaction is classified as a Weak acid versus Strong Base reaction as NH₄⁺ is from a Weak acid and OH⁻ is from a strong base.

Since this reaction is between a Weak base and a strong acid, the ionization isn't expected to be 100%, Hence, the extent of this reaction will be any option that is not 100%, a couple pieces of information might be required for the correct estimate, but above 50% seems correct.

Hope this Helps!!!

8 0

3 years ago

A compound is found to contain 38.65 % carbon, 16.25 % hydrogen, and 45.09 % nitrogen by mass. what is the empirical formula for

iren [92.7K]

The molar mass of carbon is 12, hydrogen is 1, and nitrogen is 14, hence the ratio are:

C = 38.65 / 12 = 3.22

H = 16.25 / 1 = 16.25

N = 45.09 / 14 = 3.22

Divide the three by the lowest ratio which is 3.22:

C = 3.22 / 3.22 = 1

H = 16.25 / 3.22 = 5

N = 3.22 / 3.22 = 1

So the empirical formula is:

CHN

5 0

3 years ago

16. What is tincture of iodine?

GalinKa [24]

Answer:

Tincture of iodine, iodine tincture, or weak iodine solution is an antiseptic. It is usually 2–7% elemental iodine, along with potassium iodide or sodium iodide, dissolved in a mixture of ethanol and water. Tincture solutions are characterized by the presence of alcohol.

Explanation:

7 0

3 years ago

During unfavorable conditions, an ameba forms a.....

Sati [7]

Cyst. It's hard-walled and sturdy.

5 0

3 years ago