which sentences in the passage are true?

The atomic mass of element A is 198.39 (to two decimal places).

To calculate the atomic mass of element A, we need to consider the relative abundance of each isotope and its corresponding mass. The atomic mass is the weighted average of the masses of all the isotopes, taking into account their relative abundance.

Given:

Isotope 1: Relative abundance = 19.52%, Mass = 265.1

Isotope 2: Relative abundance = 100% - 19.52% = 80.48%, Mass = 182.27

To calculate the atomic mass, we multiply the relative abundance of each isotope by its mass and sum up the results.

Atomic mass = (Relative abundance of Isotope 1 * Mass of Isotope 1) + (Relative abundance of Isotope 2 * Mass of Isotope 2)

Atomic mass = (19.52/100 * 265.1) + (80.48/100 * 182.27)

Calculating the values:

Atomic mass = (0.1952 * 265.1) + (0.8048 * 182.27)

Atomic mass = 51.72752 + 146.661296

Atomic mass = 198.388816

Rounding to two decimal places, the atomic mass of element A is 198.39.

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Answer: True

Explanation: For example, changing direction can change velocity

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Answer:

If anyone still needed help on this, someone wrote out the student table on brainly.com, look up Lab: Calorimetry and Specific Heat.

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Explanation:

Answer:

D

Explanation:

Hope that helps :)

Answer:

Hi

Explanation:

We assume you are converting between moles H2O and gram. You can view more details on each measurement unit: molecular weight of H2O or grams This compound is also known as Water or Dihydrogen Monoxide. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles H2O, or 18.01528 grams.

1 mole is equal to 6.023 × 10 ²³ molecules. 63 grams  are in 3.5 moles of H2O.

The term mole is defined as the amount of substance of a system which contains as many elementary entities.

One mole of any substance is equal to 6.023 × 10²³ units of that substance such as atoms, molecules, or ions. The number 6.023 × 10²³ is called as Avogadro's number or Avogadro's constant.

The mole concept can be used to convert between mass and number of particles.

We expect you are converting between moles H2O and gram. The molecular weight of H2O or gram's This compound is also known as Water or Dihydrogen Monoxide. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles H2O, or 18.01528 grams.

Thus, 63 grams  are in 3.5 moles of H2O.

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The primary porosity of a sediment or rock consists of the spaces between the grains that make up that material. The more tightly packed the grains are, the lower the porosity.

Answer:

A. Number of energy levels

Answer:

1. 1.25 mol ants x 6.02*10^23 ants/1 mol ants = 7.53*10^23 ants

2. 4.92*10^26 pencils x 1 mol pencils/6.02*10^23 pencils = 817 mol pencils

3. 0.26 mol molecules x 6.02*10^23 molecules/1 mol molecules = 1.6*10^23 molecules

4. 3.46*10^19 molecules x 1 mol molecules/6.02*10^23 molecules = 5.75*10^-5 mol molecules

5. 5.3*10^20 atoms x 1 mol atoms/6.02*10^23 atoms = 8.8 mol atoms

6. 0.11 mol atoms x 6.02*10^23 atoms/1 mol atoms = 6.6*10^22 atoms

I would suggest looking into "dimensional analysis" for help with this type of material. Dimensional analysis will stick with you all throughout chemistry, so picking it up will be extremely beneficial.

Answer:

substances is never entirely a one way

Explanation:

no possibility of obtaining complete combustion at hig

temperature.

always loss of heat from the temperature

its temperature is lower than the constant volume process because some of the energy is utilized to change the volume of the system

Four reasons why the temperature of flame is lower than adiabatic flame temperature is that there is  no possibility of obtaining complete combustion at high temperature due to high thermal energy.There is always loss of heat from temperature,its temperature is lower than constant volume process because some of  energy is utilized to change the volume of the system.

Thermal energy is defined as a type of energy which is contained within a system which is responsible for temperature rise.Heat is a type of thermal energy.It is concerned with the first law of thermodynamics.

Thermal energy arises from friction and drag.It includes the internal energy or enthalpy of a body of matter and radiation.It is related to internal energy and heat .It arises when a substance whose molecules or atoms are vibrating faster.

These vibrating molecules and atoms collide and as a result of which heat is generated in a substance , more the collision of particles , higher is the thermal energy.

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Answer:

The answer is A ahahahha

Explanation:

Because it just is

Answer:

[tex]T_2=637\°C[/tex]

Explanation:

Hello there!

In this case, considering this problem as pressure constant, since the change is exhibited in temperature and volume only, it is possible for us to use the Charles' law as shown below:

[tex]\frac{V_2}{T_2}=\frac{V_1}{T_1}[/tex]

Thus, by solving for the final temperature, we obtain:

[tex]T_2=\frac{T_1V_2}{V_1}\\\\T_2=\frac{273K*1L}{0.30L}\\\\T_2=910K-273\\\\T_2=637\°C[/tex]

Best regards!

The reason is not an explanation of the assertion as we can see, the concepts are not related.

The process by which a substance transforms from a gaseous state to a liquid state is known as condensation. When a gas's temperature is dropped, the gas molecules experience energy loss and coalesce to create a liquid.

The kinetic energy of gas molecules is transformed into potential energy during condensation when they slow down and move closer to one another. The molecules can then change from a gaseous state to a liquid state since they can no longer maintain their gaseous state

Hence, the reason is not an explanation of the assertion

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Answer:

0.550 M HCl

Explanation:

M1V1 = M2V2

M1 = 0.455 M NaOH

V1 = 14.50 mL NaOH

M2 = ?

V2 = 12.0 mL HCl

Solve for M2 --> M2 = M1V1/V2

M2 = (0.455 M)(14.50 mL) / (12.0 mL) = 0.550 M HCl

Answer:

The appropriate answer is "0.549 M".

Explanation:

The given values are:

N₁ = 14.50 mL

V₁ = 0.455 M

N₂ = 12 mL

Let

V₂ = C = ?

As we know,

⇒  [tex]N_1\times V_1=N_2\times V_2[/tex]

On substituting the values, we get

⇒  [tex]14.50\times 0.455 = 12\times C[/tex]

⇒            [tex]6.5975=12\times C[/tex]

⇒                   [tex]C=\frac{6.5975}{12}[/tex]

⇒                       [tex]=0.549 \ M[/tex]

Answer:

2.04x10⁻⁴ mol

Explanation:

First we convert 3.06x10⁻³ grams of glycine into moles of glycine, using its molar mass:

In order to calculate the number of hydrogen moles, we multiply the number of glycine moles by 5, as there are 5 hydrogen moles per glycine mol:

Answer: O D. A digital signal moves between a discrete number of values.

Explanation:

The digital signals are considered more reliable over the analog signals as they encode the information in a coded form. The bits or samples of the data are transmitted and converted into digital and numerical value. The stream of encoded data is in the form of continuous data at regular time intervals. It provides information in waveform and the data is in compact form. The data is in the form of binary bits 0 and 1 so greater the number of bits greater will be the greater will be the resolution of the information.

The arbitrary assignment of the reduction of Zn2+(aq) to Zn(s) as E = 0 V serves as a reference point for determining the relative reduction potentials of other redox reactions. This assignment is based on the convention that the standard reduction potential

In the case of the Zn2+(aq) to Zn(s) reduction, the reaction involves the gain of two electrons by Zn2+ ions, leading to the formation of solid zinc metal. The assigned reduction potential of 0 V indicates that, under standard conditions (1 M concentration, 25°C, and 1 atm pressure), the Zn2+ ions have a tendency to accept electrons and be reduced to Zn metal.

Any reduction potential above 0 V suggests a greater tendency for reduction, while a negative reduction potential indicates a lower tendency for reduction compared to the Zn2+(aq) to Zn(s) reaction.

This reference potential allows us to compare the reactivity of other redox systems and predict the feasibility of different reactions. The more positive the reduction potential, the greater the tendency for reduction to occur. Therefore, if we encounter a reduction potential of +0.34 V for another reaction, we can infer that it is more likely to occur spontaneously compared to the Zn2+(aq) to Zn(s) reduction. Conversely, if we encounter a reduction potential of -0.50 V, we can conclude that the reverse reaction (oxidation) is more favorable than the reduction of Zn2+(aq) to Zn(s).

Overall, the assignment of E = 0 V for the reduction of Zn2+(aq) to Zn(s) provides a benchmark for understanding the electrochemical behavior of other redox reactions and allows us to make predictions based on the relative reduction potentials.

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1. C6H10O5 + 6O2 → 6CO2 + 5H2O

2. MgO + H2O → Mg(OH)2

3. 151.2444 grams of carbon dioxide are required to produce 3.44 moles of carbonic acid in the blood.

1. The complete, balanced chemical reaction for the burning of cellulose (C6H10O5), or wood, is:

C6H10O5 + 6O2 → 6CO2 + 5H2O

This reaction represents the combustion of cellulose in the presence of oxygen, resulting in the formation of carbon dioxide (CO2) and water (H2O).

2. The balanced equation for the reaction between magnesium oxide (MgO) and water (H2O) to produce magnesium hydroxide (Mg(OH)2) is:

MgO + H2O → Mg(OH)2

According to the equation, 1 mole of magnesium oxide reacts with 1 mole of water to produce 1 mole of magnesium hydroxide. Therefore, if 2.55 moles of magnesium oxide react, the same number of moles of magnesium hydroxide will be produced.

3. The balanced equation for the reaction between carbon dioxide (CO2) and water (H2O) to form carbonic acid (H2CO3) is:

CO2 + H2O → H2CO3

According to the equation, 1 mole of carbon dioxide reacts with 1 mole of water to produce 1 mole of carbonic acid. Therefore, if 3.44 moles of carbonic acid are produced, the same number of moles of carbon dioxide is required.

To calculate the mass of carbon dioxide, we need to know its molar mass, which is approximately 44.01 g/mol. Therefore, the mass of carbon dioxide required to produce 3.44 moles of carbonic acid is:

Mass = Moles × Molar mass

Mass = 3.44 moles × 44.01 g/mol

Mass = 151.2444 g

Therefore, 151.2444 grams of carbon dioxide are required to produce 3.44 moles of carbonic acid in the blood.

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Answer: Atomic mass (Cu) = (x)(63.0 amu) + (1 – x)(65.0 amu) = 63.5 amu 63.0x + 65 – 65.0x = 63.5 –2x = –1.5 x = 0.75 The percent abundance of each isotope is 75.0 % (Cu-63) and 25.0 % (Cu-65).

Explanation: As you know, the average atomic mass of an element is determined by taking the weighted average of the atomic masses of its naturally occurring isotopes.

Simply put, an element's naturally occurring isotopes will contribute to the average atomic mass of the element proportionally to their abundance.

Answer:

15.2 grams of calcium chloride are produced and HCl is the limiting reactant.

Explanation:

Hello there!

In this case, according to the described scenario, it is possible to realize that the reaction between hydrochloric acid and calcium hydroxide is:

[tex]2HCl+Ca(OH)_2\rightarrow CaCl_2+2H_2O[/tex]

Whereas there is a 2:1 mole ratio of the acid to the base. In such a way, with the given masses, we can compute how much calcium chloride product is produced due to the chemical reaction via stoichiometry:

[tex]m_{CaCl_2}^{by HCl}=10.0gHCl*\frac{1molHCl}{36.46gHCl}*\frac{1molCaCl_2}{2molHCl} *\frac{110.98gCaCl_2}{1molCaCl_2} =15.2gCaCl_2\\\\m_{CaCl_2}^{by Ca(OH)_2}=10.5gHCl*\frac{1molCa(OH)_2}{74.09gCa(OH)_2}*\frac{1molCaCl_2}{1molCa(OH)_2} *\frac{110.98gCaCl_2}{1molCaCl_2} =15.7gCaCl_2[/tex]

Whereas we infer that the correct amount is 15.2 g since HCl is the limiting reactant as it produces the fewest grams of the desired product. Consequently, the calcium hydroxide is the excess reactant here.

Regards!

Answer:

II. 0.10 M HF + 0.10 M NaF.

Explanation:

A buffer system may be formed in one of two ways:

Which of the following mixtures could be considered a buffer?

I. 0.10 M HCl + 0.10 M NaCl. No, because HCl is a strong acid.

II. 0.10 M HF + 0.10 M NaF. Yes, since HF is a weak acid and F⁻ (coming from NaF)  is its conjugate base.

III. 0.10 M HBr + 0.10 M NaBr. No, because HBr is a strong acid.

Answer: n= 4, , l= 3, [tex]m_l[/tex] = 1,  permissible

Explanation:

Principle Quantum Numbers : It describes the size of the orbital and the energy level. It is represented by n. Where, n = 1,2,3,4....

Azimuthal Quantum Number : It describes the shape of the orbital. It is represented as 'l'. The value of l ranges from 0 to (n-1).For l = 0,1,2,3... the orbitals are s, p, d, f...

Magnetic Quantum Number : It describes the orientation of the orbitals. It is represented as [tex]m_l[/tex]. The value of this quantum number ranges from [tex](-l\text{ to }+l).[/tex]

Spin Quantum number : It describes the direction of electron spin. This is represented as [tex]m_s[/tex]. The value of this is [tex]+\frac{1}{2}[/tex] for upward spin and [tex]-\frac{1}{2}[/tex] for downward spin.

a) n=1 , l= 2, [tex]m_l[/tex] = 0,  not permissible as l can not greater than n.

b) n= 4, , l= 3, [tex]m_l[/tex] = 1,  permissible

c) n= 3, l= 3, [tex]m_l[/tex] = 1, not permissible as l can not equal than n.

d) n= 4 , l= 3, [tex]m_l[/tex] = 4,  not permissible as [tex]m_l[/tex] can not greater than l.

Answer:

The correct approach is "1 M".

Explanation:

The given values are:

Volume of HCL,

V₁ = 45 ml

In prepared solution,

V₂ = 15 ml

Concentration,

C₁ = ?

C₂ = 3.0 M

As we know,

⇒  [tex]V_1C_1=V_2C_2[/tex]

or,

⇒      [tex]C_1=\frac{V_2C_2}{V_1}[/tex]

On substituting the values, we get

⇒           [tex]=\frac{15\times 3}{45}[/tex]

⇒           [tex]=\frac{45}{45}[/tex]

⇒           [tex]=1 \ M[/tex]

Answer:

1.51448 atms

Explanation:

Answer:

Yes

Explanation:

There are in double dash :) ( = )

Answer:

yes

Explanation:

Because the double dash shows a double bond it simply means that two electrons from each atom are being shared

Molar mass of C3H8 = C 3 (12.01 g/mol) = 36.03 (g/mol)

H 8 (1.008 g/mol) = 8.064 (g/mol)

44.09 (g/mol)

74.6 g propane x 1 mole propane x 6.022 x 10

23

molecules

44.09 g propane 1 mole propane

= 1.02 x 10

24 molecules propane

1. For the pair of half-reactions:

Pt2+(aq) + 2e- → Pt(s)    ... (1)

Sn2+(aq) + 2e- → Sn(s)    ... (2)

To obtain the balanced equation for the overall cell reaction, we need to multiply the half-reactions by appropriate coefficients to ensure that the number of electrons transferred is equal. In this case, we can multiply equation (1) by 2 and equation (2) by 1:

2(Pt2+(aq) + 2e-) → 2(Pt(s))

Sn2+(aq) + 2e- → Sn(s)

Combining the equations, we have:

2Pt2+(aq) + Sn2+(aq) → 2Pt(s) + Sn(s)

The cell notation for this reaction is:

Pt2+(aq) | Pt(s) || Sn2+(aq) | Sn(s)

To calculate the standard cell potential (E°), we need to know the standard reduction potentials for Pt2+/Pt(s) and Sn2+/Sn(s) half-reactions. Referring to standard reduction potential tables, we find:

E°(Pt2+/Pt(s)) = +1.20 V

E°(Sn2+/Sn(s)) = -0.14 V

The overall cell potential (E°cell) is the difference between the reduction potentials:

E°cell = E°(cathode) - E°(anode) = 0.00 V - (-0.14 V) = +0.14 V

Therefore, the standard cell potential for this reaction is +0.14 V.

2. For the pair of half-reactions:

Co2+(aq) + 2e- → Co(s)    ... (3)

Cr3+(aq) + 3e- → Cr(s)    ... (4)

To balance the number of electrons transferred, equation (4) can be multiplied by 2:

2(Co2+(aq) + 2e-) → 2(Co(s))

Cr3+(aq) + 3e- → Cr(s)

Combining the equations, we have:

2Co2+(aq) + Cr3+(aq) → 2Co(s) + Cr(s)

The cell notation for this reaction is:

Co2+(aq) | Co(s) || Cr3+(aq) | Cr(s)

To calculate the standard cell potential (E°), we refer to the standard reduction potentials:

E°(Co2+/Co(s)) = -0.28 V

E°(Cr3+/Cr(s)) = -0.74 V

The overall cell potential (E°cell) is the difference between the reduction potentials:

E°cell = E°(cathode) - E°(anode) = -0.74 V - (-0.28 V) = -0.46 V

Therefore, the standard cell potential for this reaction is -0.46 V.

3. For the pair of half-reactions:

Hg2+(aq) + 2e- → Hg (l)    ... (5)

Cr2+(aq) + 2e- → Cr(s)    ... (6)

The equation for the overall cell reaction can be obtained by multiplying equation (6) by 2:

2(Hg2+(aq) + 2e-) → 2(Hg (l))

Cr2+(aq) + 2e- → Cr(s)

Combining the equations, we have:

2Hg2+(aq) + Cr2+(aq) → 2Hg (l) + Cr(s)

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Answer:

85.952 ml [tex]Zn^2^+[/tex]  needed to titrate the excess complexing reagent .

Explanation:

Lets calculate

After addition of 80 ml of EDTA the solution becomes = 20 + 70 = 90 ml

As the number of moles of [tex]CoSO_4[/tex] =[tex]\frac{Given mass }{molar mass}[/tex]

                                                       =[tex]\frac{1.817}{155}[/tex]

                                                          =0.01172

Molarity = [tex]\frac{no. of moles}{volume of solution}[/tex]

           =[tex]\frac{0.01172}{20}[/tex]

        =0.000586 moles

Excess of EDTA = concentration of EDTA - concentration of CoSO4

                            = 0.009005 - 0.000586

                           = 0.008419 M

As M1V1 ( Excess of EDTA ) = M2V2 [tex](Zn^2^+)[/tex]

           [tex]0.008419\times100ml=0.009795\times V2[/tex]

           [tex]V2=\frac{0.008419\times100}{0.009795}[/tex]

             V2 =85.952 ml

Therefore , 85.952 ml [tex]Zn^2^+[/tex] needed to titrate the excess complexing reagent .

Answer:

Reducing the amount of water you use, by having a 5-minute shower or not running the water when washing up the dishes, can help protect vital wetlands. Plant scientists are also working to help conserve by developing crop varieties that use less water.

Explanation:

Answer:

1. Most of the endangered organisms may represent a source of income.

2. The conservation or preservation may conflict with morals.

3. The role of the species or organisms might not be understood.

Explanation:

Biodiversity simply means the amount or number of living organisms that exist in the world.

The practice of protecting these existing living organisms for specific known purposes is regarded as the preservation or conservation of biodiversity.

This process or practice of preserving biodiversity is important to meet most of the human needs, such as generating income, source of food and fuel among others.

Answer:

Option A

Explanation:

As we know

C1V1 = C2V2

C1 = concentration of solution before dilution

V1 = Volume of solution before dilution

C2 = concentration of solution after dilution

V2 = Volume of solution after dilution

Substituting the given values in above equation, we get -

125 mL * 2.00 M  = X mL * 1.50 M

X mL = 125 mL * 2.00 M  / 1.50 M

X = 167 mL

Hence, option A is correct