According to a weather map, a cold air mass is moving into a given area where a warm air mass is currently located. What type of weather should be expected as the cold air mass approaches? A. rain, accompanied by cooler weather B. clear skies, accompanied by cooler weather C. rain, accompanied by warmer weather D. clear skies, accompanied by warmer weather

The pressure exerted by 0.57 moles of CO2 at a temperature of 25°C and a volume of 500 ml is 28 atm.

Explanation:

According to ideal gas law,

                                      PV = nRT

where P represents the pressure of a gas,

          V  represents the volume of a gas,

          n represents the number of moles,

          R represents the gas constant = 0.0821 L atm / mol K.

          T represents the temperature of a gas.

Given V = 500 ml = 0.5 l,           T = 25°C = 298 K,   n = 0.57 mol

                                        PV = nRT

                                           P = nRT / V

                                              = (0.57 [tex]\times[/tex] 0.0821 [tex]\times[/tex] 298) / 0.5

                                          P = 28 atm.

The pressure of a gas is 28 atm.

Final answer:

Using the ideal gas law, the pressure exerted by 0.57 moles of CO₂ gas at a temperature of 25°C and a volume of 500 mL is calculated to be 28.56 atm.

Explanation:

To calculate the pressure exerted by 0.57 moles of CO₂ gas at a temperature of 25°C (which is 298K when converted to Kelvin) and a volume of 500 mL (which is 0.5 L), we can use the ideal gas law equation PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the ideal gas constant (0.0821 L·atm/K·mol), and T is temperature in Kelvin.

To find the pressure (P), we rearrange the equation to P = nRT/V.

Substituting the values into the equation we get: P = (0.57 · 0.0821 · 298) / 0.5

Now, we perform the calculation:

P = (0.57 · 0.0821 · 298) / 0.5 = 28.56 atm

Therefore, the pressure exerted by the CO₂ gas is 28.56 atm.

Answer:

it is option b

Explanation:

this is because neutralisation reaction takes place only between a base and an acid.

now, in OPTION A it is a neutral and base

OPTIONB  it is acid and base

OPTION C both are base

OPTION D  IT IS NOT POSSIBLE

A neutralization reaction involves an acid and a base, with pH levels generally below and above 7 respectively. To identify a combination that would result in such a reaction, we require an acidic and a basic substance. Thus, the correct combination would be option B: a substance with a pH of 2 (acid) and a substance with a pH of 10 (base).

The subject in question pertains to neutralization reactions in chemistry. A neutralization reaction typically involves a strong acid and a strong base reacting to form water and a type of salt. The pH scale measures how acidic or basic a solution is, and ranges from 0 to 14. If we remember that a pH of 7 is neutral, acids are typically represented with a pH less than 7, and bases are represented with a pH greater than 7, we can use that to find our answer.

Based on these principles, options A and C wouldn't yield a neutralization reaction because they both involve a neutral or basic substance with another base. Option D does not guarantee a neutralization reaction either as the two solutions could be both acidic or basic. Therefore, the correct choice would be option B: a substance with a pH of 2 (which would be an acid) and a substance with a pH of 10 (which would be a base). The acid-base combination would result in a neutralization reaction.

https://brainly.com/question/us15211597

#SPJ2

Answer:

It does not dissolve readily.

Explanation:

Si  is the chemical symbol for the atom. 14 is the total number of electrons according to the given electron configuration.

chemical symbol, abbreviation for a chemical element's scientific name; for example, S for sulphur or Si for silicon. Sometimes the sign comes from the Latin term; for example, Au stands for aurum, or gold, and Na stands for natrium, or sodium. The current chemical symbols illustrate how the theory of atoms of matter has systematised chemistry. John Dalton, an English chemist who adopted the alchemists' practise of depicting the elements in pictures, achieved the significant advancement of allowing his symbols to be used.

The total number of electrons  2+2+6+2+2 = 14

atomic number =14.

Atomic number 14 is Silicon with symbol Si.

To know more about chemical symbol, here:

https://brainly.com/question/9249660

#SPJ6

Final answer:

A neutral phosphorus atom has 15 electrons. The electron configuration is 1s²2s²2p63s²3p³.

Explanation:

A neutral phosphorus atom has 15 electrons. Two electrons can go into the 1s subshell, 2 can go into the 2s subshell, and 6 can go into the 2p subshell. That leaves 5 electrons. Of those 5 electrons, 2 can go into the 3s subshell, and the remaining 3 electrons can go into the 3p subshell. Thus, the electron configuration of neutral phosphorus atoms is 1s²2s²2p63s²3p³.

Answer:

Explanation:

a) In an exothermic reaction, the energy transferred to the surroundings from forming new bonds is ___more____ than the energy needed to break existing bonds.  

b) In an endothermic reaction, the energy transferred to the surroundings from forming new bonds is ___less____ than the energy needed to break existing bonds.  

c) The energy change of an exothermic reaction has a _____negative_______ sign.  

d) The energy change of an endothermic reaction has a ____positive________ sign.

The energy changes occur during the bonds formation and bonds breaking.

There are two types of reaction endothermic and exothermic reaction.

Endothermic reactions:

The type of reactions in which energy is absorbed are called endothermic reactions.

In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.

For example:

C + H₂O   →  CO  + H₂

ΔH = +131 kj/mol

it can be written as,

C +  H₂O  + 131 kj/mol  →  CO  + H₂

Exothermic reaction:

The type of reactions in which energy is released are called exothermic reactions.

In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.

For example:

Chemical equation:

C + O₂   →  CO₂

ΔH = -393 Kj/mol

it can be written as,

C + O₂   →  CO₂ + 393 Kj/mol

Answer:

impedes the flow of electrons

Explanation:

When electricity flowing in a circuit, that means the electron is flowing there too. All objects have resistance which tells how much the material impedes the flow of electron, which in turn will lower the current flowing on the circuit. It won't stop the flow completely. Material with high resistance will be called insulator and material with low resistance called a conductor.

Galaxy Formation.  One says that galaxies were born when vast clouds of gas and dust collapsed under their own gravitational pull, allowing stars to form. The other, which has gained strength in recent years, says the young universe contained many small "lumps" of matter, which clumped together to form galaxies.

Answer:

V₂ = 648.53 mL

Explanation:

Given data:

Initial volume of gas = 490. mL

Initial temperature = -35°C (-35 + 273 = 238 k)

Final temperature = 42°C =  (42+273 = 315 k)

Final volume = ?

Solution:

The given problem will be solve through the Charles Law.

According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.

Mathematical expression:

V₁/T₁ = V₂/T₂

V₁ = Initial volume

T₁ = Initial temperature

V₂ = Final volume  

T₂ = Final temperature

Now we will put the values in formula.

V₁/T₁ = V₂/T₂

V₂ = V₁T₂/T₁  

V₂ = 490 mL × 315 K / 238 k

V₂ = 154350 mL.K / 238 K

V₂ = 648.53 mL

Answer:

mass = 25.03 g

Explanation:

Given data:

Initial temperature = 67.5°C

Final temperature = 25.2°C

Heat released = -4425 j

Mass of water = ?

Solution:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 25.2°C - 67.5°C

ΔT = -42.3°C

Specific heat of water = 4.18 j/g.°C

Q = m.c. ΔT

-4425 j = m × 4.18 j/g.°C × -42.3°C

-4425 j = m × -176.81 j/g

m = -4425 j /  -176.81 j/g

m = 25.03 g

The mass of the sample of water is approximately 250 grams.

To find the mass of the water sample, we can use the formula for the heat released or absorbed by a substance undergoing a temperature change:

[tex]\[ q = m \cdot c \cdot \Delta T \][/tex]

where:

[tex]- \( q \)[/tex] is the heat released or absorbed (in joules),

[tex]- \( m \)[/tex] is the mass of the substance (in grams),

[tex]- \( c \)[/tex] is the specific heat capacity of the substance (in joules per gram per degree Celsius),

[tex]- \( \Delta T \)[/tex] is the change in temperature (in degrees Celsius).

For water, the specific heat capacity [tex]\( c \)[/tex] is approximately [tex]\( 4.184 \, \text{J/g}^\circ \text{C} \)[/tex].

Given:

[tex]- \( q = -4425 \, \text{J} \)[/tex] (the negative sign indicates heat is released),

[tex]- \( \Delta T = 67.5^\circ \text{C} - 25.2^\circ \text{C} = 42.3^\circ \text{C} \),[/tex]

[tex]- \( c = 4.184 \, \text{J/g}^\circ \text{C} \).[/tex]

We can rearrange the formula to solve for [tex]\( m \)[/tex]:

[tex]\[ m = \frac{q}{c \cdot \Delta T} \][/tex]

Now, plug in the values:

[tex]\[ m = \frac{-4425 \, \text{J}}{4.184 \, \text{J/g}^\circ \text{C} \cdot 42.3^\circ \text{C}} \] \[ m = \frac{-4425}{4.184 \times 42.3} \] \[ m \approx \frac{-4425}{177.3172} \] \[ m \approx -25 \][/tex]

Since mass cannot be negative, we take the absolute value of the result:

[tex]\[ m \approx 250 \, \text{g} \][/tex]

Therefore, the mass of the sample of water is approximately 250 grams.

Answer:

800mL

Explanation:

Using Boyle's law which states that the volume of a given mass of gas is inversely proportional to the pressure, provided temperature remains constant

P1V1= P2V2

P1 = 2 atm, V1 = 2000mL ,

P2 = 5atm , V2 = ?

2 × 2000 = 5 × V2

Divide both sides by 5

V2 = 4000 ÷ 5

V2 = 800mL

I hope this was helpful, please mark as brainliest

Final answer:

The volume of a balloon filled with 2000 mL of air at 2 atm will change to 800 mL when the pressure is increased to 5 atm, as per Boyle's Law, which states that pressure and volume are inversely proportional for a gas at constant temperature.

Explanation:

The principles of gas laws, specifically Boyle's Law, which implies that for a given mass and constant temperature of an ideal gas, the pressure and volume are inversely proportional. We can set up a direct application of Boyle's Law where P1 * V1 = P2 * V2. Given that a balloon is filled with 2000 mL of air at a pressure of 2 atm (P1 and V1), we want to find the new volume (V2) if the pressure is changed to 5 atm (P2).

Using the formula, we can solve for V2 as follows:

V2 = (P1 * V1) / P2

V2 = (2 atm * 2000 mL) / 5 atm

V2 = 4000 mL atm / 5 atm

V2 = 800 mL

Therefore, the volume of the balloon when the pressure is increased to 5 atm is 800 mL.

Gallium, because is a post-transition metal

Final answer:

The mass of a single water molecule is approximated to be 2.99 × 10^-23 grams, using its molar mass of 18.015 g/mol and Avogadro's number, which indicates the number of molecules in one mole.

Explanation:

To calculate the mass in grams of a single water molecule, we first look at the molar mass of water (H2O) which is 18.015 g/mol. This is because one mole (6.022 × 1023 entities) of water molecules weighs 18.015 grams. The mass of a single water molecule is therefore:
(1 molecule / 6.022 × 1023 molecules/mol) × 18.015 g/mol

Performing the calculation, we find the mass of a single water molecule to be approximately:
(1 / 6.022 × 1023) × 18.015 g

= 2.99 × 10-23 g

The mass of a single water molecule is 2.99 × 10-23 grams.

Answer:

Since energy cannot be created or destroyed and it can only change form or be transferred from one object to another.

The total amount of energy and matter in the Universe remains constant, merely changing from one form to another. The First Law of Thermodynamics (Conservation) states that energy is always conserved, it cannot be created or destroyed. In essence, energy can be converted from one form into another.

Hope this helps! If so please mark brainliest and rate/heart to help my account if it did!!

The correct option is option B. All of the energy can be accounted for.

According to the energy conservation principle, no matter how energy is transformed, its overall quantity never changes. Energy can only be changed from one form to another; it cannot be created or destroyed. The law of conservation of energy is the term used to describe this idea.

According to the law of conservation of energy, the total energy before and after conversion is the same.

Therefore, all of the energy involved in a transformation can be accounted for.

Learn more about the conservation of energy here:

https://brainly.com/question/13949051

#SPJ 2

The statement which best describes the path of the gas particles in the sample of gas is the straight path which changes upon collisions with other particles.

Gaseous state is one of the state of matter in which particles are present at great distance from each other with random arrangement.

In a sample of gas, firstly gases particles will move in a straight line till then collision with another gas particle takes place. After the collision path of the gas particle changes and keeps on changes with the additional collision.

Hence firstly gas particles are move in a straight line.

To know more about gaseous state, visit the below link:

https://brainly.com/question/16982523

Answer:

30.33L

Explanation:

Using Boyle's law which states that the volume of a given mass of gas is inversely proportional to the pressure, provided temperature remains constant  and Charles law states that the volume of a given mass of gas is directly proportional to the temperature provided the pressure remains constant

P1V1/T1 = P2V2/ T2

P1 =  78atm, V1 = 21L , T1 = 900K

P2 = 45atm, V2 = ? , T2 =750K

78× 21 / 900 = 45×V2 / 750

1638/900 = 45 V2 / 750

1638×750 = 900×45V2

1228500 = 40500V2

Divide both sides by 40500

1228500÷40500= V2

V2 = 30.33L

I hope this was helpful, please mark as brainliest

Using the combined gas law, we determined the final volume of the gas to be 30.33 liters.

To solve this problem, we'll use the combined gas law, which is expressed as:

(P₁ * V₁) / T₁ = (P₂ * V₂) / T₂

Here, P₁, V₁, and T₁ are the initial pressure, volume, and temperature, and P₂, V₂, and T₂ are the final pressure, volume, and temperature.

We are given the following values:

P₁ = 78 atm

V₁ = 21 liters

T₁ = 900 K

P₂ = 45 atm

T₂ = 750 K

We need to find V₂. Rearrange the combined gas law to solve for V₂:

V₂ = (P₁ * V₁ * T₂) / (T₁ * P₂)

Substitute the given values into the equation:

V₂ = (78 atm * 21 liters * 750 K) / (900 K * 45 atm)

Calculate the result step-by-step:

78 * 21 = 1638

1638 * 750 = 1228500

900 * 45 = 40500

V₂ = 1228500 / 40500 = 30.33 liters

Therefore, the final volume, V₂, is 30.33 liters.

Answer:

18 g of gaseous water

Explanation:

We are given the equation;

2H2O (g) ----> 2H2 (g) + O2 (g) ∆H = 483.6 kJ

We are required to determine the mass of gaseous water decomposed when the amount of heat absorbed is 241.8 kJ.

From the equation;

2 moles of water are decomposed when 483.6 kJ is absorbed

Therefore;

241.8 kJ will be absorbed to decompose;

 = (2 × 241.8 kJ) ÷ 483.6 kJ

= 1 mole

But; molar mass of water is 18 g /mol

Therefore;

Mass of gaseous water decomposed is 18 g

Answer:

Electron Geometry describes arrangement is electron groups & Molecular Geometry describes the arrangement of atoms

Explanation:

The picture above better explains it, hopefully this helps :)

Answer: M = 0.01 M C12H22O16

Explanation: First convert the mass of C12H22O16 into moles using the molar mass of the compound.

5 g C12H22O16 x 1 mole C12H22O16 / 342 g C12H22O16

= 0.01 mole C12H22O16

To calculate the molarity we will use the following formula.

M = n / L

= 0.01 mole / 1 L

= 0.01 M C12H22O16

Final answer:

To find the molarity of a sugar solution with 5g of sucrose in 1L of water, calculate the moles of sucrose and divide by the volume. The molarity of this solution is 0.01 M C12H22O16

Explanation:

The question asks to find the molarity of a sugar solution which is made by dissolving 5g of sucrose (C12H22O11) in enough water to make a 1L solution. First, we need to find the molar mass of sucrose, which is the sum of the atomic masses of its constituent elements: 12 carbons, 22 hydrogens, and 11 oxygens. The molar mass of sucrose is (12 × 12.011) + (22 × 1.008) + (11 × 15.999) = 342.30 g/mol. Now, we calculate the number of moles of sucrose present in 5g and then divide by the volume of the solution in liters to get the molarity.

First convert the mass of C12H22O16 into moles using the molar mass of the compound.

5 g C12H22O16 x 1 mole C12H22O16 / 342 g C12H22O16

= 0.01 mole C12H22O16

To calculate the molarity we will use the following formula.

M = n / L

= 0.01 mole / 1 L

= 0.01 M C12H22O16

Answer:

A. Air

Explanation:

Lignin which has a glucos link is a unique hydrocarbon comprising 8-20% of the cell wall of plants. It is a complex, dense, amorphous, secondary cell wall polymer found in the trachea elements and sclerenchyma of terrestrial plants.

Since plant absorbs carbon dioxide from air to form glucose and hence, starch; That is the source of carbon to build other macromolecules.

Water which it absorbs from soil is not of carbon content neither do plant take in microorganisms.

Plants obtain the majority of the carbon necessary for building these structural molecules from air

General, plants that have a very strong internal structure can grow larger than other plants because their structure can support their size. They absorbs carbon dioxide from air to form those carbon-containing molecules

Learn more about plants:

https://brainly.com/question/25832580

Answer:

gravitational potential

Explanation:

The form of energy that is stored in large objects because of its position above the ground is gravitational potencial energy.

Answer:

T = 154 K

Explanation:

Given data:

Number of moles of Cl₂ = 0.07 mol

Pressure = 1.18 atm

Volume = 750 mL

Temperature = ?

Solution:

The given problem will be solve by using general gas equation, which is,

PV = nRT

R = general gas constant (0.0821 atm.L/mol.K)

Now we will convert the mL to L.

Volume = 750 mL × 1 L/1000 mL

Volume = 0.75 L

Now we will put the values in formula.

T = PV/nR

T = 1.18 atm × 0.75 L / 0.07 mol ×0.0821 atm.L/mol.K

T = 0.885/0.00575 /K

T = 154 K

Answer :

(1) The number of cups needed are, 0.45 cups.

(2) The number of cups needed are, 5 cups.

Explanation :

Part 1:

First we have to calculate the moles of NaCl.

[tex]\text{Moles of NaCl}=\frac{\text{Mass of NaCl}}{\text{Molar mass of NaCl}}[/tex]

[tex]\text{Moles of NaCl}=\frac{520g}{58.5g/mol}=8.89mol[/tex]

Now we have to calculate the number of cups needed.

As, the number of cups needed for 8.89 mole of NaCl = 1 cups

So, the number of cups needed for 4 mole of NaCl = [tex]\frac{4}{8.89}=0.45[/tex] cups

Thus, the number of cups needed are, 0.45 cups.

Part 2:

Given:

Mass of ice cubes = 1 kg = 1000 g

Now we have to calculate the number of cups needed.

As, the number of cups needed for 220 g of ice = 1 cups

So, the number of cups needed for 1000 g of ice = [tex]\frac{1000}{220}=4.5\approx 5[/tex] cups

Thus, the number of cups needed are, 5 cups.

Answer:

266.67 J/s

Explanation:

Work is said to be done when a force is applied to a certain object. It is given by the expression:

Workdone = Force × distance

However, the power (P) is the quantity or amount of work-done per time which is mathematically expressed as:

P = [tex]\frac{Workdone}{time}[/tex]

Given that:

time = 2.5 hours = (2.5 × 3600) seconds  = 9000 seconds

Force = 32 N

distance = 75 km = (75 × 1000) m = 75, 000 m

∴ Workdone = 32 × 75, 000

  Workdone  = 2,400,000 Joules

Power = [tex]\frac{2,400,000}{9000}[/tex]

Power = 266.67 J/s

Answer:

Explanation:

Given:

Force, f = 32 N

Distance, d = 75 km

1 km = 1,000 m

75 km × 1000 m/1 km

= 75,000 m

Time, t = 2.5 hours

60 secs = 1 min

60 mins = 1 hour

2.5 hours × 60 mins/ 1 hour × 60 sec/1 min

= 9,000 secs

Power = energy/time

Energy = force × distance

Power = (32 × 75,000)/9,000

= 266.67 W

80 ml or 0.08 L of 1M HCl is needed to make 12 M HCl.

Explanation:

We have to use the law of Volumetric Analysis, to find the volume of the 12M solution using the volume and the molarity of the known solution of hydrochloric acid, using the law as,

V₁M₁ = V₂M₂

The above equation can be rewritten to find the volume as,

[tex]$ V2 = \frac{V1M1}{M2}[/tex]

Plugin the given values as,

[tex]$ V2 = \frac{1L\times 1M}{12 M}[/tex]  = 0.08 L or 80 ml

Answer:

NaOH(aq) is a Base.

Explanation:

Those substances which give or release [tex]OH^{-}[/tex] ions in aqueous solution are called as the Arrhenius Bases.

In the aqueous solution, NaOH dissociates as follows -

[tex]NaOH^{}[/tex] ↔ [tex]Na^{+} + OH^{-}[/tex]

If it reacts with a strong acid HCl, the chemical equation for this reaction will be as follows -

[tex]HCl + NaOH = NaCl + H_{2} O[/tex]

The chemical equation that shows how NaOH is a base according to the Arrhenius definition is

NaOH(aq) → Na⁺(aq) + OH⁻(aq)

According to Arrhenius definition

Now, we will write a chemical equation that shows the dissociation of NaOH in water.

The chemical equation for the dissociation of NaOH in water is

NaOH(aq) → Na⁺(aq) + OH⁻(aq)

Since, NaOH dissociates in water to the hydroxide ion (OH⁻), then it is a base according Arrhenius definition.

Hence, the chemical equation that shows how NaOH is a base according to the Arrhenius definition is

NaOH(aq) → Na⁺(aq) + OH⁻(aq)

Learn more here: https://brainly.com/question/15062109

Answer: m= 22.2 g Ne

Explanation: First find the moles of Ne using Ideal Gas Law and derive for n. So from PV= nRT the mole is derived as n = PV /RT

n = PV / RT

= 1 atm ( 25 L ) / 0.0821 L.atm /

mole.K ( 273 K )

= 1.11 moles Ne

Convert it to mass using the molar mass of Neon

1.11 moles Ne x 20 g Ne / 1 mole Ne

= 22.2 g Ne

Final answer:

The mass of 25.0 L of neon at STP is approximately 22.43 grams, calculated by using the molar volume of a gas at STP and the molar mass of neon.

Explanation:

To calculate the mass of neon at standard temperature and pressure (STP), we can use the molar mass of neon and the ideal gas law. At STP, one mole of any ideal gas occupies 22.4 L. Since we are given the volume of neon gas as 25.0 L, we can calculate the number of moles (n) of neon first:

n = Volume / Molar Volume at STP
n = 25.0 L / 22.4 L mol⁻¹ = 1.116 mol

The molar mass of neon (Ne) is approximately 20.11 g mol⁻¹. We use the calculated moles to find the mass:

mass = n × molar mass
mass = 1.116 mol × 20.11 g mol⁻¹ = 22.43 g

So, the mass of 25.0 L of neon at STP is approximately 22.43 grams.

Explanation:

We know that metals are good conductor of heat. so it allows the heat to flow through them

. So as we know the spoon is a metal which is left on a bowl of hot soup allows heat to flow through it easily so if becomes warm.

Answer: A) metal is a conductor

Explanation:

Answer:

A gamma rays

Explanation:

Gamma rays unlike beta and alpha particles releases energy and they are actual rays and not particles.

A gamma ray is  form of electromagnetic radiation with no mass and charge. Its energy could range from 10KeV to 3MeV.

Its range is not definite in any medium but much longer than those of alpha and beta particles. Intensity of the rays diminishes exponentially from the source.

Final answer:

The molar mass of Strontium nitride (Sr3N2) is calculated by multiplying the molar masses of strontium and nitrogen by their respective number of atoms in the formula and adding the products together, resulting in 290.88 g/mol.

Explanation:

To find the molar mass of Strontium nitride (Sr3N2), you must first determine the molar masses of strontium (Sr) and nitrogen (N) from the periodic table. The molar mass of strontium is 87.62 g/mol. Since there are three strontium atoms in Sr3N2, you would multiply 87.62 g/mol by 3. The molar mass of nitrogen is 14.01 g/mol, and there are two nitrogen atoms in Sr3N2, so multiply 14.01 g/mol by 2.

Then you add the molar masses of strontium and nitrogen together:

Finally, sum these values to find the molar mass of Sr3N2:

Molar mass of Sr3N2 = 262.86 g/mol + 28.02 g/mol = 290.88 g/mol.

Answer:

False.

Explanation:

The Earth's atmosphere is composed of 78% Nitrogen & 21% Oxygen. The other 1% varies.