Which are the three most common gases Giving Brainliest

Answer:

The radius of O^2- is  1.5*10^-8 cm and the radius of

Mg ^2+ is 6.2*10^-9 cm

Explanation:

Face centered cubic : 1/8 atoms on each edges + 1/2 atoms on each face

                                           = [tex]\frac{1}{8}* 8 + \frac{1}{2}*6[/tex]  = 4 effective atoms

MgO have a structure like NaCl forms a lattice of FCC.

density of the lattice =  [tex]\frac{ z.M}{a^3*Na}[/tex]

z : no of atoms

M: mass of the atoms

a: radius of the atom

Na: Avogadro's number

a^3(radius)  = [tex]\frac{ 4*40.3}{3.58*6.022*10^23}[/tex]

a^3 = 7.477 * 10^-23 cm^3

a = 4.21 * 10^-8 cm

Now calculating the anionic(ra O^2-) and cationic (rc Mg^2+)

in Fcc a = 2[tex]\sqrt{2} ra[/tex]

ra = 1.5*10^-8 cm

a = 2ra + 2rc

rc = a/2 -ra

rc = 6.2*10^-9 cm

The radius of O^2- is  1.5*10^-8 cm and the radius of Mg ^2+ is 6.2*10^-9 cm

Answer:

5km/h

Explanation:

Given parameters:

Distance  = 7.5km

Time  = 1.5h

Unknown:

Average speed   = ?

Solution:

Average speed is the distance divided by the time taken.

 Average speed  = [tex]\frac{total distance }{time taken}[/tex]  

Insert the parameters and solve;

 Average speed  = [tex]\frac{7.5}{1.5}[/tex]   = 5km/h

Answer:

electronic configuration: 1s^2,2s^2,2p^3            

name: nitrogen

unpaired electron: 3

Explanation:

The atom with 2 electrons and 5 electrons in the first and second energy level is NITROGEN. The element has 3 unpaired electron.

Therefore, the 2p orbital has 3 unpaired electrons in it's outermost shell.

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Answer:

The viscosity [tex]\mathbf{\eta = 7.416 \times 10^{-4} \ N.s/m^2}[/tex]

Explanation:

From the given information:

Time t = 1.55 s

The radius of capillary = 5.00 μm /2

The pressure drop ΔP = 2.45 kPa

The length of the capillary = 2.00 mm

∴

The viscosity of the blood flow can be calculated by using the formula:

[tex]\eta = \dfrac{r^2 \Delta P }{8Lv}[/tex]

where;

v = L/t

Then;

[tex]\eta = \dfrac{r^2 \Delta P }{8L(\dfrac{L}{t})}[/tex]

[tex]\eta = \dfrac{(\dfrac{5 \times 10^{-6} \ m}{2})^2(2.45 \times 10^3 \ Pa) }{8(2.0 \times 10^{-3} \ m ) (\dfrac{2.0 \times 10^{-3} \ m }{1.55 \ s })}[/tex]

[tex]\eta = 7.416 \times 10^{-4} \ Pa.s[/tex]

To (N.s/m²)

[tex]\mathbf{\eta = 7.416 \times 10^{-4} \ N.s/m^2}[/tex]

Answer:

D unbalanced force

Explanation:

i think

Answer:

[tex]M=0.16M[/tex]

Explanation:

Hello!

In this case, since the molarity is defined as moles of solute divided by liters of solution, since we have phenol with a molar mass of 94.12 g/mol, we can first compute the moles in 1.5 g of phenol:

[tex]n=1.5g*\frac{1mol}{94.12 g}=0.016mol[/tex]

Next, since 1000 mL = 1 L, we notice that the volume of the solution is 0.100 L and therefore, the molarity of such solution turns out:

[tex]M=\frac{n}{V}=\frac{0.016mol}{0.100L}\\\\M=0.16M[/tex]

Best regards!

Fossil evidence for Pangaea includes the presence of similar and identical species on continents that are now great distances apart.

Answer: increase number of collisions

Explanation:

Decreasing the volume increases the likelihood of particles interacting more often.

Answer:

Atoms collided more often when the volume was lower.

Explanation:

plato

Answer:

6.05%

Explanation:

From the question given above, the following data were obtained:

Decay constant (K) = 0.0561 /yr

Time (t) = 50 years

We can obtain the percentage of tritium remaining after 50 years by using the following formula:

Log (N₀/N) = kt /2.303

NOTE:

N₀ is the original amount.

N is the amount remaining.

K is the decay constant.

t is the time

Log (N₀/N) = (0.0561 × 50) /2.303

Log (N₀/N) = 2.805/2.303

Log (N₀/N) = 1.218

Take the anti log of 1.218

(N₀/N) = anti log (1.218)

(N₀/N) = 1.218

N₀/N = 16.52

Invert and multiply by 100 to obtain the percentage.

N/N₀ = 1/16.52 × 100

N/N₀ = 6.05%

Thus, the percentage of tritium remaining after 50 years is 6.05%

Answer:

6.08% remains after 50 years

Explanation:

The radioactive decay follows the equation:

Ln[A] = -kt + Ln [A]₀

Where [A] is concentration of reactant after time t, [A]₀ is its initial concentration, k is rate constant and t is time.

Assuming its Initial concentration is 100%

Time is 50 yr

k is 0.056 yr⁻¹

And [A] is our incognite

Ln[A] = -0.056 yr⁻¹*50yr + Ln [100%]

ln[A] = 1.805

[A] =

Answer: D) Nitrogen Dioxide

Explanation:

The characteristics of moles allow you to find that the correct answer for which sample weighs more is:

             D) Nitrogen Dioxide

The molecular weight of the substance is the weight of one mole of a material, where one mole is Avogadro's number of particles.

In all chemical reactions the relationships are given as a function of moles.

Let's find the molecular weight of each of the substances, we take the atomic weights from the periodic table

Element      PA (gr / mol)

   H                     1

   C                   12

   N                   14

   O                   16

   Ar                  40

A) Ammonia with NH₃ formula

     weight of a mole of molecules

           MP = 14 + 3

           PM = 17 gr / mol

B) Argon symbol Ar

    It is a noble gas and does not react

         PM = 40 gr / mol

C) Carbon dioxide formula CO₂

      Weight per mole of substance

        PM = 12 + 2 16

        Pm = 44 gr / mol

D) Nitrogen dioxide formula NO₂

       Weight per molecular

         MP = 14 + 2 16

         PM = 46 gr / mol

E) Oxygen symbol O formula O₂

      Molecular weights

         PM = 2 16

         PPM = 32 gr / mol

It indicates that we have two liters of sample, so the number of moles of each substance is the same, therefore the substance that weighs more is Nitrogen Dioxide (NO₂)

When reviewing the different answer, the correct one is:

            D) Nitrogen Dioxide

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Answer:

[tex]\Delta P=4.10atm[/tex]

Explanation:

Hello!

In this case, since the ideal gas equation is used under the assumption of no interaction between molecules and perfectly sphere-shaped molecules but the van der Waals equation actually includes those effects, we can compute each pressure as shown below, considering the temperature in kelvins (22.3+273.15=295.45K):

[tex]P^{ideal}=\frac{nRT}{V}=\frac{15.0mol*0.08206\frac{atm*L}{mol*K}*295.45K}{8.00L}=45.5atm[/tex]

Next, since the VdW equation requires the molar volume, we proceed as shown below:

[tex]v=\frac{8.00L}{15.0mol}=0.533\frac{L}{mol}[/tex]

Now, we use its definition:

[tex]P^{VdW}=\frac{RT}{v-b} -\frac{a}{v^2}[/tex]

Thus, by plugging in we obtain:

[tex]P^{VdW}=\frac{0.08206\frac{atm*L}{mol*K}*295.45K}{0.533mol/L-0.0430L/mol} -\frac{2.300L^2*atm/mol^2}{(0.533L/mol)^2}\\\\P^{VdW}=49.44atm-8.09atm\\\\P^{VdW}=41.4atm[/tex]

Thus, the pressure difference is:

[tex]\Delta P=45.5atm-41.4atm\\\\\Delta P=4.10atm[/tex]

Best regards!

Answer:

c. 0.200 M HCI(aq)

Explanation:

The titration of a base as NH3 with hydrochloric acid is:

NH3 + HCl → NH4Cl

Where 1 mole of NH3 reacts per mole of HCl

The recommended volume to read in a burette is between 60 and 80% of its capacity.

That is 60% 50.0mL = 30mL and 80% 50.0mL = 40mL must be spent.

A 6.00M HCl spend:

20mL * (0.3mol/L) * (1L/ 6.00M) = 1mL. This solution is not the ideal for the titration.

A 0.3M HCl spend:

20mL * (0.3mol/L) * (1L/ 0.3M) = 20mL. This solution is not the ideal for the titration.

A 0.200M HCl spend:

20mL * (0.3mol/L) * (1L/ 0.200M) = 30mL. This solution ideal for the titration.

A 0.100M HCl spend:

20mL * (0.3mol/L) * (1L/ 0.100M) = 60mL. This solution is not the ideal for the titration.

Right option is:

Answer:

Explanation:

we shall use gas law formula to solve the problem .

P = .01 atm

V = 1.111 L

T = 273 K

mass of gas = .0218

molar mass = M

no of moles n = .0218 / M

PV = n RT

.01 x 1.111 = (.0218 / M)  x .082 x 273

.0218 / M = .000496

M = .0218 / .000496

= 43.95

Answer:

Under balanced its motion under motion its s = d/t under s - d/t is time d = distance s= speed

Explanation:

Answer:

18

Explanation:

36 times 0.5

Answer:

Answer: Tin (II) nitride

Hi!

When the ocean reaches its saturation level of carbon dioxide, a couple of things will happen:

First, more carbon dioxide will remain in the atmosphere, and second, the ocean's pH will drop.

Carbonate and bicarbonate ions in seawater act as a buffer system which keeps the ocean's pH levels stable. When CO2 dissolves in seawater, it reacts with the ocean's buffer system in such a way that it produces two hydrogen ions, which lowers the pH. As more and more CO2 reacts with the ocean's buffer system and the system becomes saturated, less atmospheric carbon dioxide will cross over into the ocean. This excess CO2 will remain in the atmosphere and contribute to global climate change.

Hope this helped!

When the ocean reaches it's saturation level of carbon dioxide  more amount of carbon dioxide remains in the atmosphere and  pH of the ocean drops.

It is defined as the level or extent up-to which a substance is soluble in a particular solvent. Due to global warming ,there is an excessive release of carbon dioxide in atmosphere. The excessive amount cannot be soluble in the ocean water which leads to ocean acidification.

As a result of ocean acidification the pH of water in the ocean drops thus there is less amount of oxygen present for aquatic organisms which is needed to survive. When carbon dioxide dissolves in water it yields carbonic acid which further reduces the pH of water  and thus making it unfit for aquatic environment.

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Answer:

B

Explanation:

hydrogen only has one electron/molecule in it's only shell so it can get together and make a bond

The question is incomplete, the complete question is shown in the image attached

Answer:

F

T

Explanation:

From the equilibrium equation;

N2O4(g) ⇄NO2(g)

We must have to remember that;

1) At equilibrium, the concentration of the species on both sides of the reaction equation may not necessarily be the same but must be held at a constant value because the rate of forward reaction equals the rate of reverse reaction.

2) The rate of forward reaction must equal the rate of reverse reaction.

If the rate of forward reaction is k1 and the rate of reverse reaction is k2. Then it follows that at equilibrium k1 = k2.

Answer:

Water has a higher boiling point because the hydrogen bonds that form water molecules are stronger than the Van der Waals interactions among methane molecules, therefor more energy must be provided in order to break the hydrogen bonds and allow the water molecules to escape the liquid state.

Explanation:

Water has a much higher boiling point than methane because only Van der Waals forces exist between methane molecules.​

Chemical bonds are forces of attraction between ions, molecules, and atoms.

There are different types of bonds present

Covalent bonds are the strongest bonds.

The molecules of water are joined by a hydrogen bond, thus its boiling point is high.

The molecules of Methane are attached by the van der Waals force, and it is weaker than the hydrogen bond.

Thus, methane has a lower boiling point than water.

Weaker bonds easily get broken.

Thus, the correct option is D.

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Answer:

A

Explanation:

gyx3gevedyhsdv

The branch of science which deals with chemicals and bonds is called chemistry.

The correct answer is A.

The polarity is defined as the separation of electric charge leading to a molecule or its chemical groups having an electric dipole moment, with a negatively charged end and a positively charged end.

The polar molecule has the following:-

In, the first compound the polarity is the same because the compound is the same that is O-F and CL-F.

Hence, the correct answer is A.

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Answer:

0.322 mols of NaSO4

Explanation:

Molality = Mols of Solute / kg of Solvent

Molality is given as 0.140 m = mols/kg

kg of solution is given as 2.30 kg

Mols of Solute = Molality * kg of Solvent

Mols of Solute = [tex]\frac{0.140 }{ 1 kg } *2.30 kg[/tex]

Mols of Solute = 0.322 mols

The number of mole of Na₂SO₄ required to prepare the solution is 0.322 mole

The Molality of a solution is defined as the mole of solute per Kg of water i.e

Molality = mole / mass (Kg) of water.

With the above formula, we can obtain the mole of Na₂SO₄ in the solution as follow:

Molality of Na₂SO₄ = 0.140 M

Mass of water = 2.30 Kg

Mole = Molality × mass of water

Mole of Na₂SO₄ = 0.140 × 2.30

Therefore, the mole of Na₂SO₄ in the solution is 0.322 mole

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Answer:

7.44%

Explanation:

[tex]\frac{6.44}{6.44+80.1} *100=7.44[/tex]

Answer:

D. Brain

~PumpkinSpice1

Answer:

See explanation

Explanation:

a. I can conclusively tell if the crown was made of gold by measuring its density. First the mass of the crown is measured on a weighing balance. The crown is now put into a given volume of water and the volume of water displaced is accurately measured. The density of the crown is computed as mass/volume of fluid displaced. If the density of the crown is 19.3 g/mL, then it is made of solid gold.

b) When less valuable metals such as bronze or copper is mixed with gold in the crown, the density of the crown decreases and the crown becomes more brittle.

c) An object will float in a liquid when the density of the object is less than the density of the liquid. Hence the tendency of an object to float in a liquid depends on the density of the object and the density of the liquid.

d) Even though i do not know the results from your experiment but as regards the decision as to whether the object will float in the given liquid or not, reference must be made to the measured density of the object as well as the given density of the liquid. If the object is less dense (from values of density obtained from the experiment)  than the liquid, then the object will float in the liquid and vice versa.

Answer:

Explanation:

the sum of number of proton and neutron is known as atomic mass

so if number of proton is 4 and neutron is 5 then atomic mass of an atom is 9

Answer:

the word subcellular means contained within a cell. at a level of organization lower than the cellular.

Explanation: