16. If a sample of nitrogen monoxide is held in a 1.25 L flask at 31°C with a measured pressure of
3.6 atm, how many moles are present?

The pH of the ethanoic acid can be obtained as 3.39.

We know that the pH has to do with the negative logarithm of the hydrogen ion concentration of a solution. We know that we have to apply the formula for the pH so as to obtain the pH of the solutions.

pH of hydrochloric acid = - log( 0.100) = 1

pH of sulphuric acid = - log( 0.025 ) =1.6

pH of nitric acid = - log (0.005) = 2.3

pH of phosphoric acid = - log ( 0.200) = 0.69

We say that HCl is a strong acid because it s able to dissociate completely in solution while the ethanoic acid does not dissociate completely in solution.

For the dissociation of ethanoic acid we have;

Ka = [[tex]H_{3} O^+[/tex]] [[tex]CH_{3} COO^-[/tex]]/[[tex]CH_{3} COOH[/tex]]

1.7 x10^-5 = x^2/0.01 - x

1.7 x10^-5(0.01 - x) =x^2

1.7 * 10^-7 - 1.7 x10^-5x - x^2 = 0

x^2 + 1.7 * 10^-5x - 1.7 * 10^-7 = 0

x=0.0004 M

pH = - log(0.0004 )

pH = 3.39

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There are two characteristics of molecules, one is geometry and other is shape. Shape is excluding lone pair surrounding the central element and geometry is including the lone pair. Therefore, the angle of the given molecule can be found out by VSEPR theory.

VSEPR stands for valence shell electron pair repulsions. VSEPR theory is used to predict the shape and geometry of molecules on the basis of valence electrons pairs that are present around the central element of the molecule.

According to VSEPR theory, Lone pair lone pair repulsion is greater than bond pair bond pair repulsion. There are so many limitations of VSEPR theory. There is a repulsion between bond pair electrons and lone pairs present on the central element.

a) bond angle is 180°

b)bond angle is 120°

c)bond angle is 107.28'

d)bond angle is 109.28'

Therefore, the angle of the given molecule can be found out by VSEPR theory.

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Taking into account the reaction stoichiometry, the percent yield of BaCO₃ is 81.07%.

In first place, the balanced reaction is:

BaCl₂ + Na₂CO₃ → BaCO₃ + 2 NaCl

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

Molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.

The molarity of a solution is calculated by:

molarity= number of moles÷ volume

In first place, you know:

Replacing in the definition of molarity:

0.500 M= number of moles of Na₂CO₃÷ 0.025 L

Solving:

number of moles of Na₂CO₃= 0.500 M× 0.025 L

number of moles of Na₂CO₃= 0.0125 moles

0.500 M= number of moles of BaCl₂÷ 0.025 L

Solving:

number of moles of BaCl₂= 0.500 M× 0.025 L

number of moles of BaCl₂= 0.0125 moles

This indicates that 0.0125 mol of Na₂CO₃ and 0.0125 mol of BaCl₂ are present.

Since the stoichiometric ratio of the reactants is 1:1, if 0.0125 mol of Na₂CO₃ and BaCl₂ are present, since the amounts are equal, it makes no difference to work with any of the reactants.

The percent yield is the ratio of the actual return to the theoretical return expressed as a percentage.

The percent yield is calculated as the experimental yield divided by the theoretical yield multiplied by 100%:

percent yield= (actual yield÷ theoretical yield)×100%

where the theoretical yield is the amount of product acquired through the complete conversion of all reagents in the final product, that is, it is the maximum amount of product that could be formed from the given amounts of reagents.

The following rule of three can be applied: if by reaction stoichiometry 1 mole of BaCl₂ form 1 mole of BaCO₃, 0.0125 moles of BaCl₂ form how many moles of BaCO₃?

moles of BaCO₃= (0.0125 moles of BaCl₂×1 mole of BaCO₃)÷ 1 mole of BaCl₂

moles of BaCO₃= 0.0125 moles

Being the molar mass of BaCO₃ 197.35 g/mole, the theoretical yield of BaCO₃ is calculated as:

theoretical yield of BaCO₃=  0.0125 moles× 197.35 g/mole

theoretical yield of BaCO₃= 2.466875 grams

In this case, you know:

Replacing in the definition of percent yield:

percent yield= (2 grams÷ 2.466875 grams)× 100 %

Solving:

percent yield= 81.07%

Finally, the percent yield for the reaction is 81.07%.

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Answer:

51.16% H₂O

Explanation:

To find the percent water in the hydrate, you need to

(1) calculate the masses of 7H₂O and MgSO₄ · 7H₂O

(2) calculate the percent composition

(Step 1)

Atomic Mass (Mg): 24.305 g/mol

Atomic Mass (S): 32.065 g/mol

Atomic Mass (O): 15.999 g/mol

Atomic Mass (H): 1.008 g/mol

Mass (MgSO₄): 24.305 g + 32.065 g + 4(15.999 g/mol) = 120.366 g

Mass (7H₂O): 14(1.008 g/mol) + 7(15.999 g/mol) = 126.105 g

Mass (MgSO₄·7H₂O): 120.366 g + 126.105 g = 246.471 g

(Step 2)

                                                Mass Water
Percent Composition  =  ----------------------------  x  100%
                                                Total Mass

                                                    126.105 g H₂O
Percent Composition  =  --------------------------------------  x  100%
                                          246.471 g MgSO₄·7H₂O

Percent Composition = 51.16% H₂O

When 1-Chloropentane is treated with sodium ethoxide, it follows the SN2 mechanism. Therefore, option (1) is correct.

The SN2 reaction can be defined as a type of reaction mechanism where one bond is broken and one bond is formed in one step. "SN" refers that the reaction is a nucleophilic substitution and proceeds via a bi-molecular mechanism. Here, both the reacting chemical species are involved in the rate-determining step.

The reaction takes place at an aliphatic sp³ carbon center with an electronegative, stable leaving group attached to a halide atom. The breaking of the C-X bond and the formation of the new bond occur simultaneously via a transition state in which a carbon under nucleophilic attack will be pentacoordinate.

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Answer:

As altitude increases, partial pressure of O2 increases. -

Explanation:

-As altitude increases, partial pressure of O2 increases. -As atmospheric pressure increases, available O2 increases. -As atmospheric pressure increases, partial pressure of O2 increases. Boyle's law states there is a direct relationship between the pressure and volume of a gas at a constant temperature.

The reaction is spontaneous under conditions of low pressure and high temperature

We can say that a reaction is spontaneous when we know that the reaction is able to go on on its own. This implies that there is a mnimum energy that is required for the reaction to proceed.

The reaction is thus a sort of a self propagating system that goes on freely of its own accord.. We can see that what is going on here is the decomposition of the nitrogen V oxide gas as shown.

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The percent yield of KCl is 82.2 %. The percent yield of sodium hydroxide is 36.99 %. The reaction produces about 1.35 L of water.

1)

Number of moles of potassium chlorate = 1200.0 grams/122.55 g/mol

= 9.79 moles

If 2 moles of potassium chlorate produces 2 moles of potassium chloride then 9.79 moles of potassium chloride is produced.

Theoretical yield =  9.79 moles * 74.55 g/mol

= 729.8 g

Percent yield = actual/theoretical * 100/1

=  600.0 grams / 729.8 grams * 100/1

= 82.2 %

2)

Number of moles of water = 705 grams/18 g/mol = 39.2 moles

Number of moles of sodium oxide = 302 grams/62 g/mol

= 4.9 moles

If the reaction is 1:1 the sodium oxide is the limiting reactant

1 mole of sodium oxide produces 2 moles of sodium hydroxide

4.9 moles of sodium oxide produces 4.9 moles  * 2 moles/ 1 mole

= 9.8 moles

Theoretical yield of the sodium hydroxide = 9.8 moles * 40 g/mol

= 392 g

Percent yield = 145 g/392 g * 100/1

= 36.99 %

3)

Mass of the pentane = density * volume

= 0.6262 g/mL * 3000 mL

= 1878.6 g

Number of moles of the pentane = 1878.6 g/72 g/mol

= 26.1 moles

Number of moles of oxygen = 3200.0 g/32 g/mol

= 100 moles

If 1 mole of pentane reacts with 8 moles of oxygen

26.1 moles of pentane reacts with 26.1 moles * 8 moles/1 mole

= 208.8 moles

Hence oxygen is the limiting reactant

If 8 moles of oxygen produces 6 moles of water

100 moles of oxygen would produce 100 moles * 6 moles/8 moles

= 75 moles

Mass of water produced = 75 moles * 18 g/mol = 1350 g

Since volume = mass/density

Volume of water = 1350 g/1.00 g/mL

= 1350 mL or 1.35 L

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Answer:

Music has the ability to deeply affect our mental states and raise our mood. When we need it, music gives us energy and motivation. When we're worried, it can soothe us; when we're weary, it can encourage us; and when we're feeling deflated, it can re-inspire us.

Explanation:

Mark now as BRANLIEST!!!!

Answer:

A neutron is a subatomic particle found in the nucleus of every atom except that of simple hydrogen.

Explanation:

Answer:

With the exception of simple hydrogen, every atom has a neutron in its nucleus. The fact that the particle has no electrical charge it is neutral gives it its name. Neutrons have a very high density.

_________________

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Have a great day!

The molecular or formula mass of each of the given substances is given below:

(a) P₄ = 128 amu

(b) H₂O = 18 amu

(c) Ca(NO₃)₂ = 124 amu

(d) CH₃CO₂H (acetic acid) = 60 amu

(e) C₁₂H₂₂O₁₁ (sucrose, cane sugar) = 342 amu

The molecular or formula mass of a substance id the sum of the masses of the atoms of the elements present in that substance.

The molecular or formula mass of each of the given substances is determined as follows:

(a) P₄ =  32 * 4

P₄ = 128 amu

(b) H₂O = 2 * 1 + 16

H₂O = 18 amu

(c) Ca(NO₃)₂ = 40 + (14 * 2 + 16 * 3 * 2)

Ca(NO₃)₂ = 124 amu

(d)  CH₃CO₂H = 2 * 12 + 4 * 1 + 16 * 2

CH₃CO₂H = 60 amu

(e) C₁₂H₂₂O₁₁  = 12 * 12 + 1 * 22 + 16 * 11

C₁₂H₂₂O₁₁ = 342 amu

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Answer:

36.132 × 10²³ atoms of Si

Explanation:

Formula we use,

→ No. of moles × 6.022 × 10²³

Now the atoms will be,

→ No. of moles × 6.022 × 10²³

→ 6 × 6.022 × 10²³

→ 36.132 × 10²³

There are 36.132 × 10²³ atoms.

Based on how chemical equations are written, the given chemical reaction: Four atoms of aluminum metal react quickly with 3 molecules of oxygen in the air to produce 2 molecules of aluminum oxide can be written as follows:

Word equation: Aluminum metal + oxygen gas ---> Aluminum oxide

Reactants: Aluminum metal and oxygen gas

Products: Aluminum oxide

Known states of matter: solid + gas ---> solid

Equation: 4 Al (s) + 3 O₂ (g) ---> 2 Al₂O₃ (s)

A chemical reaction is a type of change that results in changes in the chemical properties of substances.

Chemical reactions involve the rearrangement of atoms of substances and result in the formation of new substances.

Chemical reactions can be represented by a chemical equation.

Chemical equations use symbols to represent the reactants and the products of a reaction.

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Considering the formal charges, the lewis structure in which the electronegative atom (O) contains a negative charge and the electropositive (N) contains a positive charge represents bonding in the N₂O. Therefore, option (B) is correct.

A formal charge in chemical bonding can be described as the charge assigned to an atom in a molecule by considering that electrons in all chemical bonds are equally shared between atoms, regardless of relative electronegativity.

The formal charge can be described as the difference between the number of valence electrons of an atom in a neutral state and the number assigned in a Lewis structure to that atom.

When determining the best Lewis structure for a molecule, the structure is selected such that the formal charge is as close to zero on each atom.

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The Fischer projection given here is for L-enantiomer and ketopentose. Option B is correct, as there is a ketone group present in the carbohydrate monomer. Carbohydrate can have an aldehyde or ketone as a functional group.

Carbohydrate monomer is a single unit that can either have an aldehyde functional group called aldose or a ketone functional group called ketose. Here in the given diagram, the monomer has a ketone group (C=O) and has five carbons, so it is considered a keto pentose. Carbohydrates are classified into L and D forms based on their OH group, and this L and D form differs from the "l" and "d" form (classified on the direction of movement around the plane polarized light).

Hence, this given diagram is L-enantiomer and keto pentose, which is option B.

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The concentration of the solution if the absorbance of the solution at 427 nm is 0.15 and the molar absorptivity of yellow dye at 427 nm is 5.47 × 10-⁶M.

Absorbance in physics is a logarithmic measure of the amount of light that is absorbed when passing through a substance.

It is the capacity of a substance to absorb light of a given wavelength. According to this question, the absorbance of the solution at 427 nm is 0.15.

A = εmCl

Where;

C = 0.15 ÷ (27400 × 1)

C = 5.47 × 10-⁶M

Therefore, 5.47 × 10-⁶M is the concentration of the solution.

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Answer: 212

Explanation:

The binding energy per nucleon for the ¹⁹F nucleon is equal to 7.786 MeV/nucleon.

Binding energy can be defined as the minimum quantity of energy that is required to remove the particle from the system. Nuclear binding energy can be described as the energy required to dismantle a nucleus of an atom into free neutrons and protons.

The binding energy will be determined from the mass defect. Mass defect is calculated from the difference between the mass observed and the expected combined mass.

Given the mass of the ¹⁹F = 18.9984 a.m.u.

The mass defect for the ¹⁹F can be calculated as:

Δm = [tex](M _n +M_p) - M_F[/tex]

[tex]\triangle m =( 9\times 1.0078 + 10 \times 1.0087 )- 18.9984[/tex]

[tex]\triangle m =0.1588 \;a.m.u.[/tex]

The binding energy for the fluorine can be calculated as:

E = Δmc²

E = 0.1588 × 931.5

E = 147.92 MeV

The binding energy per nucleon of ¹⁹F can be calculated as:

B.E.N. = 147.92/18.9984 = 7.786 MeV per nucleon

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Answer:

12.044 × 10^23

Explanation:

Molecular mass is the sum of atomic masses of the elements present in a molecule. 12 gram of carbon that is one mole contains

6.022×10^23 atoms.

. It is called Avogadro's constant.

So, Number of particles = Given number of moles

×

Avogadro number.

Therefore, the number of atoms of He in 2.0 moles = 2.0×6.022×10^23 = 12.044×10^23

There are

12.044×10^23

atoms in 2.0 moles of Helium.

The sample has a new pressure of 274kPa. If at 105 kPa and 275K, a 220 mL sample of helium gas is contained in a cylinder with a moving piston. The sample is pushed till it has a 95.0 mL volume and 310K .

The macroscopic characteristics of ideal gases are related by the ideal gas law (PV = nRT). A gas is considered to be perfect if its particles (a) do not interact with one another and (b) occupy no space (have no volume). Where P= pressure  V= volume and T = temperature.

From ideal gas equation

P₁V₁/T₁ =P₂V₂/T₂

105×220÷275 = P₂ ×95÷310

P₂= (105×220×310)÷(275×95)

P2= 7161000/26125

P2 = 274.105 kPa

Hence, the new pressure of helium gas is 274kPa

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One sigma and two pi bonds make up the triple bond in the diatomic molecule of nitrogen.

As with all molecules, molecular nitrogen is made up of two nitrogen atoms triple bonded to one another. As with all molecules, this triple bonding allows the outer electron shells of the two nitrogen atoms to fill up, making the molecule more stable than the individual nitrogen atoms.

With another nitrogen atom, three of them form a triple bond (which also has five electrons in its outermost shell). Because of this, a nitrogen molecule has a triple bond between two nitrogen atoms and a lone pair on each nitrogen atom.

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The energy in the battery was transformed into electrical energy, light energy, and heat energy is the best explanation of the energy in the circuit (Option A).

The energy is conserved in a battery as chemical energy that can be used by converting it into electrical energy, a process that is well known to release heat.

Therefore, with this data, we can see that the energy conserved in a battery is a form of chemical energy that can be converted into electrical energy for use.

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A) Pentanal aldehyde can be prepared from CH₃CH₂CH₂CH₂CH₂OH by the oxidation with PCC.

B)  Pentanal can be prepared from CH₃CH₂CH₂CH₂CH=CH₂ by ozonolysis with the help of  O₃ /Zn.

C) Pentanal can be prepared from ester CH₃CH₂CH₂CH₂CO₂CH₃ by hydrolysis and then reduction with LiAlH₄.

D) Pentanal can be prepared from CH₃CH₂CH₂CH=CH₂ by using BH₃/H₂O/NaOH followed by PCC.

Pentanal or valeraldehyde can be described as an organic compound an alkyl aldehyde, with molecular formula C₅H₁₀O. Pentanal can be used in flavorings, rubber accelerators, and resin chemistry. The smell of Pentanal is described as fermented, bready, fruity, nutty, and berry.

Pentanal can be obtained by hydroformylation of butene and can be used as starting material such as the so-called raffinate II, which is formed by steam cracking and consists of (Z)- and (E)-2-butene, 1-butene, butane, and isobutane.

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Answer:

J.J. Thomson.

Explanation:

The credit for the discovery of the electron and its properties goes to J.J. Thomson based on his experiments carried out in a discharge tube. He suggested that electrons are necessary constituents of all atoms. J.J. Thomson carried out experiments by taking a gas at low pressure of 0.01mm Hg in a discharge tube.

Answer:

J.J. Thomson used a Crookes, or cathode ray, tube to conduct experiments that led to the discovery of the electron in 1897. He provided evidence that cathode rays have a negative charge. He also investigated positively charged neon gas particles.

Explanation:

There will be 18 groups in periodic table and hafnium is a kind of transition element.

Groups were the names given to the periodic table's columns. In the table, individuals who belong to the same group make bonds of the same kind and contain an equal quantity of electrons in respective molecules' outermost shells. Periods contain the horizontal rows.

1. 18 group 2. Zinc  3. Transition element 4.  7th period

5. Hydrogen, lithium sodium, potassium, rubidium, cesium and francium.

6. Tin(Sn) 7. The eight electron  8. Actinides  9. 7 valence electron

10.  47 neutron  11. 6th period and 11th group 12. Argon 13. Metalloid

14. Halogen located in 17th group   15. Copernicium   16. 2 electron                 17. 5 shells     18. Non metal    19. Sulphur      20. 13 group            21. Metal 22. D or transition     23. 117    24. Copper   25. Submetallic  26. 74             27. Sn   28. Alkaline earth metal   29. 18 element  30. 125

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Ideal gas law is valid only for ideal gas not for vanderwaal gas. Combined Boyle's and Charles' gas law is used here. Therefore the new pressure of nitrogen gas is 2.18 atm when the temperature is changed to 310K and volume is expanded to 50.8 L.

Ideal gas equation is the mathematical expression that relates pressure volume and temperature.

Mathematically the relation between Pressure, volume and temperature can be given as

PV=nRT

where,

P = pressure of gas

V= volume of gas

n =number of moles of gas

T =temperature of gas

R = Gas constant = 0.0821 L.atm/K.mol

Combining Boyle's and Charles' gas law

P₁V₁/T₁ = P₂V₂/T₂

{ ( 4.45) ( 23.6)} ÷296K ={ (P2) (50.8 )} ÷310

P2 =0.35÷0.16 = 2.18 atm

Therefore the new pressure of nitrogen gas is 2.18 atm when the temperature is changed to 310K and volume is expanded to 50.8 L.

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What are the following masses

Please complete the questions

The gravitational radius (Rg) of the black holes would be approximately; 4.0 Mʘ black hole: 0.00332179 miles, 10.0 Mʘ black hole: 0.00830584 miles, 25.0 Mʘ black hole: 0.0207646 miles, and 10^8 Mʘ black hole: 8,305.84 miles.

To calculate the Gravitational Radius (Rg) of a black hole, you can use the formula:

Rg = 2 × G × M

where Rg is gravitational radius, G is gravitational constant (approximately 6.67430 × 10⁻¹¹ m³ kg⁻¹ s⁻²), and M is mass of the black hole in solar masses (Mʘ).

Given that Rg is defined as 2 miles per solar mass (Mʘ), we can convert the result to miles using the conversion factor of 1 mile = 1.60934 kilometers.

Let's calculate the Rg for the different masses

For a 4.0 Mʘ black hole:

Rg = 2 × G × M = 2 × (6.67430 × 10⁻¹¹ m³ kg⁻¹ s⁻²) × 4.0

Rg = 5.33944 × 10⁻¹⁰ m = 0.00332179 miles

For a 10.0 Mʘ black hole:

Rg = 2 × G × M = 2 × (6.67430 × 10⁻¹¹ m³ kg⁻¹ s⁻²) × 10.0

Rg = 1.33486 × 10⁻⁹ m = 0.00830584 miles

For a 25.0 Mʘ black hole:

Rg = 2 × G × M = 2 × (6.67430 × 10⁻¹¹ m³ kg⁻¹ s⁻²) × 25.0

Rg = 3.33715 × 10⁻⁹ m = 0.0207646 miles

For a 10⁸ Mʘ black hole:

Rg = 2 × G × M = 2 × (6.67430 × 10⁻¹¹ m³ kg⁻¹ s⁻²) × (10⁸)

Rg = 1.33486 × 10¹⁰ m = 8,305.84 miles

Therefore, the gravitational radius (Rg) of the black holes would be approximately:

4.0 Mʘ black hole: 0.00332179 miles

10.0 Mʘ black hole: 0.00830584 miles

25.0 Mʘ black hole: 0.0207646 miles

10^8 Mʘ black hole: 8,305.84 miles

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--The given question is incomplete, the complete question is

"If the Gravitational Radius (Rg) of a black hole is 2 miles per solar mass (Mʘ), what would be the Rg  of the black holes with the following masses: A 4.0 Mo black hole? B 10.0 Mo black hole? C 25.0 Mo black hole? D 108 Mo black hole? "--

Answer:

The number of molecules of water us 1.50× 10²⁵ molecules

Explanation:

From N=nL

where L =avogadro number ( 6.02× 10^²³ entities)

The number of the molecules of water =1

n (amount of substance)=25 moles

hence (N) = 25×1×6.02×10^²³

=1.50×10²⁵ molecules of H2O

The option that correctly describes a covalent species that has four electron groups around the central atom are:

It should be noted that when a molecule have four electron groups and it is been found around the central atom and this will orients the four groups in the direction of a tetrahedron.

However when there are  four atoms attached to these electron groups, in Tetrahedral Geometry, molecular shape  will also be also tetrahedral.

Instance of this is Methane (CH 4), in conclusion, in the case whereby all four electron pairs are bonding pairs, then it can be concluded that the  shape of the system is tetrahedral.

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missing options:

The ideal bond angle for a four-electron system is 109.5°.

If all four electron pairs are bonding pairs, the shape of the system is tetrahedral.

The eletron are not bonding in the system.

A bent shape is observed if there are two bonding pairs and two lone pairs.