Nobel gases (inert gases) have full set of valence electrons so they DO NOT REACT with other elements. Noble gases are elements.

A. stable
B. unstable

There are 12 atoms of Oxygen, since 3 times 4 is 12.

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The observation of a smaller outside hole than inside leads Becca to infer that an impact from the outside caused the hole, with a larger object striking and passing through the window from the inside.

From the observation that the hole in the window is smaller on the outside than on the inside, Becca, as a forensic technician, might deduce the following:

The hole was caused by an impact from the outside: The smaller outside hole suggests that the force that created the hole originated from the outside and exerted more pressure on the window surface facing inward.

The object causing the hole was larger on the inside: The discrepancy in hole sizes implies that the object that struck the window had a larger size or diameter on the inside, and as it penetrated the glass, it compressed or fragmented the glass, resulting in a larger hole on the inside.

The object may have passed through the window: The difference in hole sizes indicates that the object may have penetrated the window, potentially passing through to the inside. This could suggest a break-in or an incident involving the window being struck from the outside.

Overall, the observation of a smaller outside hole than inside leads Becca to infer that an impact from the outside caused the hole, with a larger object striking and passing through the window from the inside.

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Answer:

49.1 g

Explanation:

First we convert 9.67x10²³ atoms of oxygen into moles, using Avogadro's number:

Then we calculate how many P₃O₉ moles there would be with 1.60 O moles:

Finally we convert 0.18 P₃O₉ moles into grams, using its molar mass:

Answer:

At the top of a seamount, the temperature is generally cooler and the pressure is lower compared to the bottom of a trench. This is because the its closer to the ocean surface, where sunlight and atmospheric conditions can affect the temperature and pressure.

The bottom of a trench is located at a much greater depth and is subject to extreme pressure and temperatures. The temperature at the bottom of a trench can be very high due to the heat generated by tectonic activity and volcanic processes.

Explanation:

Answer:

5.67 + 0.00032 = 5.67032

Usually for decimal answers, we write 2 digits that come after decimal. We can't write all the numbers that come after the decimal because sometimes it can go on for infinte times, so we write the 2 numbers that come after decimal. So, 5.67 is the answer.

5.7 is also right if you round off the answer but 5.67 is more accurate.

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Answer:

For the question given, this shows that the answer is in 2 d.p. (2 decimal places). This means that the final answer has been rounded to 2 numbers after the decimal point!

We know that it would be 5.67 as the number after the 7 is 0, this means that the answer would be rounded down or in other terms the 7 would stay the same.

When answering a question, most of the time we would be told what decimal place to round the number to!

Hope this helps, have a lovely day! :)

Answer:

[NaCl] = 0.31 m

Explanation:

Molality is a sort of solute's concentration, that indicates the moles of solute contained in 1kg of solvent.

In this problem:

solute → NaCl

solvent → H₂O

We need the mass of solvent in kg and we have the volume, so let's convert the volume to mass by the use of density.

1 g/mL = mass / 159 mL

(Notice we needed to convert the volume from L to mL)

159 g is the mass of water. We convert to kg

159 g . 1 kg/1000 g = 0.159 kg

We convert the mass of solute to moles → 2.89 g . 1mol/ 58.45 g = 0.049 moles of NaCl

Molality → mol/kg → 0.049 mol /0.159 kg = 0.31 m

Answer:

The variables in Gay-Lussac's law are the initial temperature (T1), the initial pressure (P1), the final temperature (T2) and the final pressure (P2)....

Explanation:

Answer: the pressure of the gas after the compression is 3.88 atm

Explanation:

The question requires us to calculate the new pressure of a gas, given its initial volume at STP, new volume after compression and temperature after compression.

The following information was provided by the question:

Initial volume = V1 = 0.700 L

Final volume = V2 = 0.200 L

Final temperature = T2 = 30 °C = 303.15 K

To solve this problem, we can apply the equation for ideal gases (shown below) considering the conditions after the compression:

where R is the constant of gases (R = 0.082057 L.atm/K.mol), n is the number of moles of gas, T2 is the temperature after compression and V2 is the volume after compression.

Note that the number of moles of gas remains the same even after compression. Thus, we can calculate this number of moles considering the inital volume at STP, knowing that 1 mol of a gas at Standard Temperature and Pressure corresponds to 22.4 L of this gas:

22.4 L ------------------------- 1 mol

0.700 L ----------------------- x

Solving for x, we'll have:

Therefore, the number of moles before and after compression is 0.0312 mol.

Now that we have the values for n, T2 and V2, we can calculate the pressure after compression (P2):

Therefore, the pressure of the gas after the compression is 3.88 atm.

Answer:

yes wind is nonliving because it has no form of life to it

The initial pH for the weak acid-strong base curve is higher than the initial pH for the strong acid-strong base curve. Hence, option A is correct.

Weak acids are acids that don't completely dissociate in solution.

A weak acid is an acetic acid. It has a of 1.8⋅\(10^{-5}\). Calculate how much it will dissociate in water. Since acetic acid is a weak acid so large part will not dissociate completely.

\(k_a=\frac{[CH_3COO^-]H^+]}{[CH_3COOH]}\)

B is not true, it shows the titration curve for weak/strong acid titrated with a strong base. When choosing an indicator for colourimetric titration select one so that the pH jump at the equivalence point contains the interval p±1. Phenolphthalein has a p≈9, so to decide if it is a suitable indicator check if the pH jumps from 8 to 10 at the equivalence point.

C is not true either because of the very slow reaction.

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Answer:

the first one may be more complex so the second one will be simplified :)

Explanation:

Answer:

we use atom in our sentences all the time

Explanation:

that what i put

Hypochlorous acid is a weak acid. Its equation is following:-

HClO ⇄ H⁺ + ClO⁻

K = [H⁺]  [ClO⁻] / [HClO]

Weak Acids are the acids that do not completely dissociate into their constituent ions when dissolved in solutions.

When dissolved in water, an equilibrium is established between the concentration of the weak acid and its constituent ions.

The awareness of a substance is the quantity of solute present in a given amount of answer. Concentrations are typically expressed in phrases of molarity, defined as the wide variety of moles of solute in 1 L of answer.

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Explanation:

yeast and sugar was present

Answer:

Crest is the highest point of a wave

Following are the effects of acid rain.

What is Acid Rain?

Acid rain is caused by the accumulation of nitric and sulfuric acids in the atmosphere. These compounds are strong acids and are very soluble in water, dissolving in droplets in clouds.

Limestone effect:

Calcium carbonate, [Ca][CO3], is a very common mineral. A limestone is a well-known form of calcium carbonate. The acid contained in acid rain reacts with carbonate ions and promotes the dissolution of calcium carbonate.

This will create a bicarbonate solution. The presence of limestone and other calcium carbonates in lakes and streams helps maintain a constant pH as the mineral reacts with excess acidity. However, acid rain can eventually exceed the buffering capacity of surface waters.

How does acid rain affect buildings made of marble and limestone?

It is mainly affected in 2 ways: dissolution and alteration. Calcite dissolves when sulfuric, sulfuric and nitric acids in polluted air react with calcite in marble and limestone. Exposed areas of buildings and statues show rough surfaces, worn materials, and loss of sculptural detail. Stoneface material can be lost anywhere or only in more reactive areas.

Hence, this is how acid rain affects.

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Answer:

maybe number b is correct. ...thank you

Hemoglobin with bound carbon dioxide and hydrogen ions is carried in the blood back to the lungs, where it releases the hydrogen ions and carbon dioxide and rebinds oxygen. Thus, hemoglobin helps to transport hydrogen ions and carbon dioxide in addition to transporting oxygen.

The concentrations  Cu(NH3)42+ at equilibrium is  [Cu(NH3)42+] = 1.70 × 1013 * (0.0200M) * (0.300M)^4.

The concentrations  of Cu2+ is [Cu(NH3)42+] + [Cu2+]

The concentrations  of NH3 is 4[Cu(NH3)42+] + 4[NH3]

Equilibrium concentration is described as a state when the rate of forward reaction in a chemical reaction becomes equal to the rate of backward reaction.

The equilibrium constant expression for the formation of the complex ion Cu(NH3)42+ is:

Kf = [Cu(NH3)42+] / [Cu2+] * [NH3]^4

where [Cu(NH3)42+], [Cu2+], and [NH3] are the molar concentrations at equilibrium.

The initial concentrations of Cu2+ and NH3 are 0.0200 M and 0.300 M respectively.

We have that Kf = 1.70 × 1013, we then  rearrange the equation to solve for [Cu(NH3)42+]:

1.70 × 1013 = [Cu(NH3)42+] / (0.0200M) * (0.300M)^4

[Cu(NH3)42+] = 1.70 × 1013 * (0.0200M) * (0.300M)^4

Therefore at equilibrium, the concentration of Cu(NH3)42+ is [Cu(NH3)42+] = 1.70 × 1013 * (0.0200M) * (0.300M)^4

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Answer:

4142.16J

Explanation:

Given parameters:

Mass of water in the beaker  = 45g

Initial temperature  = 67°C

Final temperature  = 45°C

Unknown:

Quantity of heat released  = ?

Solution:

To solve this problem, we use the expression below:

       H  = m cФ

H is the quantity of heat

m is the mass

c is the specific heat  = 4.184J/g°C

Ф is the change in temperature

      H  = 45 x 4.184 x (45  - 67) = 4142.16J

The amount of heat released is 4142.16J

To convert the number of molecules of P₂O₅ to grams, we need to use the Avogadro's number and the molar mass of P₂O₅ .

The molar mass of P₂O₅ can be calculated as follows:

2 × molar mass of P + 5 × molar mass of O

= 2 × 30.97 g/mol + 5 × 15.99 g/mol

= 61.94 g/mol + 79.95 g/mol

= 141.89 g/mol

Therefore, the molar mass of P₂O₅ is 141.89 g/mol.

Now, we can use Avogadro's number to convert the number of molecules to moles:

3.45 × 10²² molecules / 6.022 × 10²³ molecules/mol

= 0.0573 moles

Finally, we can use the molar mass of P₂O₅ to convert moles to grams:

0.0573 moles × 141.89 g/mol = 8.14 grams

Therefore, the chemist has 8.14 grams of P₂O₅ .

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Mass of H2CO3 = 1.05g

Givens: NaHCO3 = 3.24

Na2CO3 = 2.19

Mass of H2CO3 = mass of NaHCO3 - mass of Na2CO3

Mass of H2CO3 = 3.24g - 2.19g

Mass of H2CO3 = 1.05g

The number of protons and the number of neutrons combine to determine the mass number of an element. Mass number = proton + neutron. If you want to calculate the number of neutrons an atom has, you can simply subtract the number of protons or atomic numbers from the mass number.

Divide the mass of a substance in grams by the molecular weight. This will give you the number of moles of the substance in a particular mass. For 12 g of water, (25 g) / (18.015 g / mol) = 0.666 mol.

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Q = Ksp = 1 × 10^(-12).

Substituting the values into the Nernst equation, we have:

0.799 V = E° - (RT/2F) * ln(1 × 10^(-12))

Now, solving for E°:

E° = 0.799 V + (RT/2F) * ln(1 × 10^(-12))

The value of R is the ideal gas constant, T is the temperature in Kelvin, and F is the Faraday constant.

To find the standard reduction potential at 25°C for the half-reaction Ag2CrO4(s) + 2e¯ → 2Ag(s) + CrO4²-(aq), we can use the Nernst equation, which relates the standard reduction potential (E°) to the equilibrium constant (K) and the reaction quotient (Q).

The Nernst equation is given as follows:

E = E° - (RT/nF) * ln(Q)

Given information:

Ksp = 1 × 10^(-12)

E = +0.799 V (standard reduction potential of Ag+ to Ag)

Since the reaction involves the dissolution of Ag2CrO4(s), the reaction quotient Q can be expressed as [Ag+]²/[CrO4²-].

Since the stoichiometry of the reaction is 2:1 for Ag2CrO4 to Ag+, we can say that [Ag+]² = Ksp.

Therefore, Q = Ksp = 1 × 10^(-12).

Substituting the values into the Nernst equation, we have:

0.799 V = E° - (RT/2F) * ln(1 × 10^(-12))

Now, solving for E°:

E° = 0.799 V + (RT/2F) * ln(1 × 10^(-12))

The value of R is the ideal gas constant, T is the temperature in Kelvin, and F is the Faraday constant.

Please note that without specific values for temperature (T) and the ideal gas constant (R), the exact standard reduction potential at 25°C cannot be determined.

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Answer:

D. Valance Electrons

Explanation:

Answer:

\(C_{base}=0.302M\)

Explanation:

Hello,

In this case, we can evidence that when calcium hydroxide solution reacts with hydrochloric acid solution, the balanced neutralization reaction turns out:

\(2HCl(aq)+Ca(OH)_2\rightarrow CaCl_2(aq)+2H_2O(l)\)

Moreover, the concentration of neutralized calcium hydroxide can be computed by using the 2:1 mole ratio between the base and the acid:

\(C_{acid}V_{acid}=2*C_{base}V_{base}\\\\C_{base}=\frac{C_{acid}V_{acid}}{2*V_{base}} =\frac{0.225M*26.85mL}{2*10.0mL}\\ \\C_{base}=0.302M\)

Regards.

Answer:

40,113 years

Explanation:

To find the age of the sample, you need to use the half-life formula:

\(N(t)=N_0(\frac{1}{2})^{t/h\)

In this formula:

------> N(t) = current mass (g)

------> N₀ = initial mass (g)

------> t = time passed (yrs)

------> h = half-life (yrs)

You can plug the given values into the equation and rearrange the formula to find "t".

N(t) = 0.781 g                       t = ? yrs

N₀ = 100 g                           h = 5730 yrs

\(N(t)=N_0(\frac{1}{2})^{t/h\)                                           <----- Half-life formula

\(0.781=100(\frac{1}{2})^{t/5730}\)                                     <----- Insert values

\(0.00781=(\frac{1}{2})^{t/5730}\)                                       <----- Divide both sides by 100

\(log_{1/2}(0.00781)=log_{1/2}((\frac{1}{2})^ {t/5730})\)               <----- Take \(log_{1/2}\) of both sides

\(7.00 = \frac{t}{5730}\)                                                   <----- Solve \(log_{1/2}\)

\(40,113 = t\)                                                   <----- Multiply both sides by 5730

The given sample is 40,113 years .

Half-life, in radioactivity, is the interval of time required for one-half of the atomic nuclei of a radioactive sample to decay.

Half-life formula,

\(\rm N(t)\;=N_0(\dfrac{1}{2})^\frac{t}{t1/2}\)   .......(1)

where,

N(t)=current mass

N₀=initial mass

t=time period

h=half -life

Given,

N(t)=0.781g, t=? yrs, N₀=100g, h=5730 years

\(\rm N(t)\;=N_0(\dfrac{1}{2})^\frac{t}{t1/2}\)

put the values, in ......(1)

0.781=100(1/2) \(t/5730\\\)

log₁/₂(0.00781)=log₁/₂ ( 1/2)\(t/5730\)

7=t/5730

40,113=t

Hence, the given sample is 40,113 years .

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