A fossil bone has 25% of radioactive parent isotope remaining. How many half-lives have passed

Answer:

Any element in group 18 has eight valence electrons (except for helium, which has a total of just two electrons). Examples include neon (Ne), argon (Ar), and krypton (Kr).

Answer:

See attached image.

Explanation:

The explanations are on the attachment.  The numerical results are below.

1.  63g/7cm^3 = 9 g/cm^3

2.  The m or mm must be converted so that the units are the same.  1 m = 1000 mm.  I'll convert the meters to mm:  0.080 m = 80 mm.

480 mm^2/80 mm = 6 mm

3.  L times L makes no physical sense, unless this is a new Star Wars technique for making dark matter.  Entertaining, but useless.

Answer:

being responsible is owing up to the possible

consequences of your decision whether it was right or wrong.

communication is a two way process in which there is a messenger and receiver

one of the ways by which a person could be responsible is by saying 'I'

in all the things he would say, instead of 'we'

for example , " We don't like the way you acted a while ago " , change it to i don't like tye way you acted a while ago.

here u r establishing ownership on the things you want to say to the person

Acceptance of Responsibility creates more rapport, increases teamwork, increases honesty, and makes each party look at things from a position of rationality and mutual understanding.

When a person accepts responsibility for their actions and or tasks or their work or their organization, it means that they have elected to become more accountable, looking at things from what they can do to help achieve the collective goal rather than their personal aspirations.

This reduces conflict as most conflicts are borne out of self-interests.

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Answer:

270 g/cm^3

Explanation:

d = mv

d = 27 g × 10cm^3

d = 270 g/cm^3

Answer:

A: False

Explanation:

B: True

C: part of earths mantle.

The reason why Biosphere 2 team not simply punch a hole in the dome to allow the excess CO2 to escape is because that would mean that the ecosystem could not survive on it own if oxygen had to be added from the outside.

The biosphere is said to be made up of the parts of Earth where life can be found. The biosphere extends from the deepest root systems of trees, to the dark environment of ocean trenches, to lush rainforests and high mountaintops.

The biosphere is divided into regions called biomes which are of five types. These biomes were classifies into five main types -

The Biosphere is self sustaining because organisms found in the biosphere depends on each other.

For example plants depend on animals for their carbon (iv) needs while animals depend on plants for their oxygen needs.

Therefore, Biosphere 2 team would not simply punch a hole in the dome in order to remove the excess CO2 because other organisms like plants in the biosphere need it in order to release oxygen.

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Answer:

Explanation: Diamond and graphite are made out of carbon atoms. The difference between the two substance is the arrangement of the carbon atoms inside each one.

Answer:

Diamond and graphite are allotropes of carbon

Explanation:

» Diamond has tetrahedral edges associating through weaker vander waal forces of attraction, it is colorless and glittering, and it is very hard.

» Graphite has hexagonal edges associating vander waal forces, it is black in color and it is soft. Example of graphite is the black rod in a dry cell.

\({}\)

The concentration of the final solution is 0.157 M.

To calculate the concentrations of the second and final solutions, we can use the formula:

C1V1 = C2V2

where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume.

For the first dilution, we have:

C1 = 1.40 M

V1 = 59.0 mL

V2 = 238 mL

Solving for C2, we get:

C2 = (C1V1) / V2

  = (1.40 M × 59.0 mL) / 238 mL

  = 0.346 M

So the concentration of the second solution is 0.346 M.

For the second dilution, we have:

C1 = 0.346 M

V1 = 119 mL

V2 = 119 mL + 143 mL = 262 mL

Solving for C2, we get:

C2 = (C1V1) / V2

  = (0.346 M × 119 mL) / 262 mL

  = 0.157 M

So the concentration of the final solution is 0.157 M.

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Answer:

carbon...?

Explanation:

Answer:

Carbon

Explanation:

Carbon makes up most of the building blocks of life.  Hope that is right. Good luck

A catalyst is a substance that increases the rate of a chemical reaction by lowering the activation energy required for the reaction to occur.

A catalyst itself does not participate in the reaction and is not consumed stoichiometrically or nonstoichiometrically. Instead, it speeds up the reaction by providing an alternative reaction pathway with a lower activation energy.

Therefore, a catalyst does not get consumed at all during a reaction. It can be used repeatedly in the same reaction or in different reactions, making it a cost-effective way to accelerate chemical reactions.

The use of catalysts is a common technique in many chemical processes, including the production of fuels, pharmaceuticals, and plastics.

Catalysts can also improve the efficiency and selectivity of reactions, leading to higher yields and reduced waste.

In addition, catalysts can be used to modify the properties of materials, such as their strength or durability, through catalytic reactions on their surfaces. Overall, catalysts play a crucial role in the modern chemical industry and research.

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Answer:

Explanation:

__________________________________________________________

According to Answers,

There is one covalent bond in a chlorine molecule. The formula for a chlorine molecule is Cl2, which means that there are two chlorine atoms bonded together per molecule. The structural formula for a molecule of chlorine is Cl-Cl, in which the line in between the symbols for the two atoms represents a single covalent bond.

__________________________________________________________

Hope this helps! <3

__________________________________________________________

When an imine is reduced to an amine, a hydrogen signal is observed in the nuclear magnetic resonance (NMR) spectrum that is indicative of the newly formed amine group.

Specifically, a broad singlet peak is typically observed in the NMR spectrum at around 2-3 ppm, which corresponds to the protons attached to the nitrogen atom in the amine.

This peak is distinct from the peak observed for the protons attached to the carbon atoms in the molecule, which typically appear as sharp peaks at around 0-2 ppm in the NMR spectrum.

Additionally, the chemical shift of the amine proton peak is typically lower than that of the imine proton peak, which is typically observed at around 6-8 ppm in the NMR spectrum.

Therefore, the presence of a broad singlet peak at around 2-3 ppm in the NMR spectrum is strongly indicative that the imine has been successfully reduced to the amine.

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Answer:

3845

Explanation:

Answer:

it is 3845 grams

Explanation:

Answer: B2Br6 + 6HNO3 → 2B(NO3)3 + 6BrH

Equation

B2Br6+HNO3=B(NO3)3+HBr

B=2                                 B=1

BR=6                             BR=1

H=1                                  H=1

N=1                                  N=3

O=3                                 O=9

ANSWER

B2Br6 + 6HNO3 → 2B(NO3)3 + 6BrH

B=2                                 B=2

BR=6                             BR=6

H=6                                  H=6

N=6                                  N=6

O=18                                 O=18

HOPE THIS HELPS

Answer:

by Judith Curry On what we can learn from Goldilocks and The Three Bears ... In planetary science, the 'Goldilocks zone' is terminology for the the band ... We all know the fairy tale story of “Goldilocks and the three bears”, where GL ... as the discovery that the Earth was not the center of the solar system.

Explanation:

The pressure of \(N_{2}\) will rise under the given conditions. And, Yes, it is possible to reverse this tendency by adding \(H_{2}\). The minimum pressure of H2 required to reverse the tendency is 0.01 atm.

The reaction involved is: \(N_{2}\)(g) + 3\(H_{2}\)(g) ⇌ 2\(NH_{3}\)(g)  Hence, when \(H_{2}\) is added to the above system, the \(N_{2}\) and  \(H_{2}\)  will react to produce \(NH_{3}\). This reaction will reduce the amount of \(N_{2}\) present in the system, causing the pressure of \(N_{2}\) to decrease. Therefore, by adding \(H_{2}\)  , we can change the tendency of \(N_{2}\) pressure from rise to fall.To calculate the minimum pressure of  \(H_{2}\)  required to reverse the tendency, we have to use the equilibrium constant, Kp. The expression for Kp for the above reaction is: Kp =( \(NH_{3}\)) / p(\(N_{2}\)) p3( \(H_{2}\) )

At equilibrium, Kp = 1.7 × 104 at 1126 °C.Now, we will solve for the minimum pressure of \(H_{2}\)   needed to reverse the tendency. Let's assume that the pressure of \(N_{2}\) has increased by x atm. Therefore, the new pressure of \(N_{2}\) will be (0.0406 + x) atm. At equilibrium, we have:

p2(\(NH_{3}\) ) / p(\(N_{2}\)) p3( \(H_{2}\) ) = 1.7 × 104

On substituting the given values and simplifying, we get:

p2(\(NH_{3}\)) / p(N2) = 6.39 × 10-5

Now, p2(\(NH_{3}\)) = 5.97 atm, and p(\(N_{2}\)) = (0.0406 + x) atm.

On substituting these values, we get:5.97 / (0.0406 + x) = 6.39 × 10-5

Solving for x, we get:x = 0.00579 atm ≈ 0.01 atm (rounded to 2 significant digits)Therefore, the minimum pressure of \(H_{2}\)   required to reverse the tendency is 0.01 atm.

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Answer:

Oscilloscope

Explanation:

"We can check out the particle property of light by comparing light with sound using a device called a oscilloscope."

a. A single replacement reaction takes place because zinc is more reactive and hydrogen

In voltaic series  

Li-K-Ba-Ca-Na-Mg-Al-Mn- (H2O) -Zn-Cr-Fe-Cd-Co-Ni-Sn-Pb- (H) -Cu-Hg-Ag-Pt-Au  

The more to the left, the metal is more reactive (easily release electrons) and the stronger reducing agent  

The more to the right, the metal is less reactive (harder to release electrons) and the stronger oxidizing agent

So that the element located on the left can push the element on the right in the redox reaction

Reaction

Zn+2HCl ⇒ ZnCl₂ + H₂

If we look at this reaction, the elements that play a role are those that undergo a redox reaction

Oxidation : Zn⇒Zn²⁺ + 2e

Reduction : 2H⁺ + 2e ⇒H₂

So Zn (located on the left) can push H (the element on the right) in the redox reaction ⇒ Zn more reactive

A single replacement reaction is a chemical reaction in which one element replaces the other elements of a compound to produce new elements and compounds

A+BC⇒AC+B

So the above reaction involves the elements Zn and H which undergo a redox reaction and are included in a single replacement

Answer:

A

Explanation:

Answer:The amount of energy used or released as heat in a reaction.

Explanation:

Answer:

0.0111moles

Explanation:

as moles = mass/ mr(16+1+1)

so 0.2g / 18

gives you 0.111moles

hope this helps :)

Order of stability will be D>C>B>A
D= This free radical has two effects that make it most stable,i.e the free radical is

allylic

as well as tertiary.
C= It is the only allylic position. So, it is 2nd most stable
B= It is tertiary free radical.
A= It is secondary free

radical

A radical is an unstable, highly reactive molecule or atom with one or more unpaired valence electrons. Because of their unpaired electrons, radicals are extremely reactive and able to take part in a wide range of chemical processes.

Chemical reactions, radiation exposure, or other sorts of chemical processes can all result in the formation of radicals. Radicals that are frequently encountered include hydroxyl radicals (•OH) and methyl radicals (•CH3). Radicals frequently take part in organic chemistry reactions because they can start chain reactions and take part in processes like radical polymerization. Radicals are difficult to study and manage because of their reactivity and instability, but they are crucial to many chemical and biological processes.

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question:

A buffer containing a higher concentration of sodium acetate than acetic acid would have a pH that is slightly higher than the pKa of acetic acid.

This is because the sodium acetate will react with any added acid, such as H+ ions, to form more acetic acid and sodium ions. This reaction will help to maintain the pH of the solution, but the excess sodium ions will slightly increase the pH of the solution.

In this case, the higher concentration of sodium acetate would shift the equilibrium towards the acetate ion, resulting in a higher pH.

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These solutions contain a weak acid and its corresponding conjugate base or a susceptible base and its corresponding conjugate acid, that's the important thing element of a buffer device.

zero.13 m acetic acid 0.17 m potassium acetate

0.32 m ammonium nitrate zero.38 m ammonia

zero.31 m hypochlorous acid 0.22 m potassium hypochlorite

A buffer device in chemistry is an answer which can withstand adjustments in pH when an acidic or fundamental substance is brought to it. A buffer system includes a weak acid and its corresponding conjugate base or a susceptible base and its corresponding conjugate acid. Buffers are essential in many organic structures, in which pH modifications could have a widespread effect on the feature of enzymes and other biomolecules.

The buffer device works via the precept of Le Chatelier's precept, which states that when a device is harassed, it will reply in a manner to counteract the pressure. within the case of a buffer device, when an acidic or basic substance is added, the vulnerable acid or base inside the buffer will react with it to maintain the pH within a positive range.

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Complete Question:

Which of the following aqueous solutions are good buffer systems? (select all that apply.)

A). 0.13 m acetic acid  0.17 m potassium acetate

B). 0.27 m nitric acid  0.22 m sodium nitrate

C). 0.32 m ammonium nitrate  0.38 m ammonia

D). 0.17 m calcium hydroxide  0.22 m calcium bromide

E). 0.31 m hypochlorous acid  0.22 m potassium hypochlorite

Answer:

The periodic table can be divided into four blocks based on the electron configuration of the elements. These blocks are:s-block: Elements in the s-block have their valence electrons in the s-orbital. This block includes the first two groups of the periodic table, which are the alkali metals (group 1) and the alkaline earth metals (group 2).p-block: Elements in the p-block have their valence electrons in the p-orbital. This block includes groups 13-18 of the periodic table, which are the non-metals, metalloids, and noble gases.d-block: Elements in the d-block have their valence electrons in the d-orbital. This block includes the transition metals, which are located in the middle of the periodic table.f-block: Elements in the f-block have their valence electrons in the f-orbital. This block includes the lanthanides and actinides, which are located at the bottom of the periodic table.These four blocks provide a useful way to organize the elements based on their electron configurations, which in turn helps to explain many of the chemical and physical properties of the elements.:

Explanation:

i think its B but i'm not fully sure (Correct)

Answer:

B.

Explanation:

One way to distinguish between NH4Cl and AgCl is through a simple solubility test. NH4Cl is a water-soluble salt, meaning it will dissolve in water, while AgCl is insoluble in water.

So if you add both salts to water and only one dissolves, you can easily identify which one is NH4Cl. Another way is through a chemical reaction test. NH4Cl is an acid salt that will react with a base to produce NH3 gas, while AgCl is a neutral salt that will not react with a base.

So if you add both salts to a base, and only one produces NH3 gas, you can identify which one is NH4Cl. AgCl can also be identified through its characteristic white color, while NH4Cl is typically a clear or white powder.

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