The shielding of electrons gives rise to an effective nuclear charge, Zeff, which explains why boron is larger than oxygen. Estimate the approximate Zeff felt by a valence electron of boron and oxygen, respectively.
a. +5 and +8.
b. +3 and +6.
c. +5 and +6.
d. +3 and +8.
e. +1 and +4.

Answers

Answer 1

Answer:

b. +3 and +6.

Explanation:

Zeff = Z - S

The Z denotes the no of protons i.e. atomic number

S denotes the non-valence electrons

For boron,

the electronic configuration is 1s₂ 2s₂ 2p₄

Now  

Z = 5, S = 2

So,  

Zeff = 5-2

= +3

For O, the electronic configuration is 1s₂ 2s₂ 2p₄

So,  

Z = 8, S = 2

= 8-2

= +6

Hence, the second option is correct


Related Questions

The volume of a gas is 200.0 mL and the pressure is 2.00 atm. When the volume of the gas is 10 mL what is the pressure if the temperature remains the same?

Answers

Answer:

40 atm

Explanation:

Boyles law states that the pressure exerted on a gas is inversely proportional to the volume it occupies provided that the temperature is held constant. It is given by:

P ∝ 1/V

PV = constant

P₁V₁ = P₂V₂

Given that V₁ = initial volume = 200 ml, P₁ = initial pressure = 2 atm, V₂ = final  volume = 10 ml, P₂ = final pressure. Hence:

2 atm * 200 ml = P₂ * 10 ml

P₂ = (2 atm * 200 ml) / 10 ml

P₂ = 40 atm

Hydrogen bonds within liquid water are attractions between protons and hydroxide ions. are dipole-dipole attractions. are ion-induced dipole attractions. are attractions between protons and oxygen nuclei. are attractions between two hydrogen atoms.

Answers

Answer:

true because the bonds cannot be broken down

if the radius of a potassium atom is 2.27 x 10-7 mm what is the radius in μm

Answers

Explanation:

the answer is in the Image above

The radius of the potassium atom is [tex]2.27\times 10^{-4} \mu m[/tex].

Explanation:

Given:

The radius of potassium atom =[tex]2.27\times 10^{-7} mm[/tex]

To find:

The radius of potassium atom in micrometers.

Solution:

The radius of potassium atom =[tex]2.27\times 10^{-7} mm[/tex]

In 1 millimeter there are 1000 micrometers.

[tex]1 mm = 1000 \mu m[/tex]

Then in [tex]2.27\times 10^{-7} mm[/tex]:

[tex]=2.27\times 10^{-7} \times 1000\\=2.27\times 10^{-4} \mu m[/tex]

The radius of the potassium atom is [tex]2.27\times 10^{-4} \mu m[/tex].

Learn more about conversions here:

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The element tin has the following number of electrons per shell: 2, 8, 18, 18, 4. Notice that the number of electrons in the outer shell of a tin atom is the same as that for a carbon atom. Therefore, what must be true of tin

Answers

The question is incomplete, the complete question is:

The element tin has the following number of electrons per shell: 2.8. 18, 18, 4. Notice that the number of electrons in the outer shell of a tin atom is the same as that for a carbon atom. Therefore, what must be true of tin? Tin is a polar atom and can bind to other polar atoms. Tin has a high molecular weight to give tin-containing molecules greater stabilty. All of the above Tin conform single covalent bonds with other elements, but not double or triple covalent bonds Tincan bind to up to four elements at a time

Answer:

Tin can bind to up to four elements at a time

Explanation:

Certain important points were made in the question about tin and one of them is that tin is an element in the same group as carbon hence it has the same number of valence electrons as carbon.

Carbon is always tetra valent. The tetra valency of carbon is the idea that carbon forms four bonds.

If tin has the same number of valence electrons as carbon, then, tin can bind to up to four elements at a time

Determine the electron geometry, molecular geometry, and idealized bond angles for each of the following molecules. CF4CF4 NF3NF3 OF2OF2 H2SH2S In which cases do you expect deviations from the idealized bond angle

Answers

Answer:

CF4

Molecular geometry- tetrahedral

Electron geometry- tetrahedral

NF3

-molecular geometry - trigonal pyramidal

Electron geometry - tetrahedral

OF2

Molecular geometry - bent

Molecular geometry - tetrahedral

H2S

Molecular geometry- bent

Electron geometry - tetrahedral

Explanation:

According to Valence Shell Electron Pair Repulsion Theory, the shape of a molecule depends on the number of electron pairs on the valence shell of the central atom in the molecule.

For all the compounds listed, the central atom has four points of electron density. This correspond to a tetrahedra electron pair geometry. The presence of lone pairs on the central atom of OF2,NF3 and H2S accounts for the departure of the observed molecular geometry from the geometry and idealized bond angle predicted on the basis of the VSEPR theory.

Compound A has the formula C8H8. It reacts rapidly with acidic KMnO4 but reacts with only 1 equivalent of H2 over a palladium catalyst. On hydrogenation under conditions that reduce aromatic rings, A reacts with 4 equivalents of H2, and hydrocarbon B, C8H16, is produced. The reaction of A with KMnO4 gives CO2 and a carboxylic acid C, C7H6O2.

Required:
Draw the structure of compound B below.

Answers

Answer:

C8H16 (Ethylcyclohexane).

Explanation:

From the given information:

Compound A is an alkene because it interacts with 1 unit of hydrogen across a palladium catalyst.

Also, we are given another hint that:

Compound A needs 4 equivalence of H2 to hydrogenate under circumstances that decrease aromatic rings, indicating that it is a phenyl substituted alkene.

Compound A with formula C8H8 reacts instantly with KMnO4 to produce CO2, as well as carboxylic acid, points out that Compound acts as a terminal alkene.

Therefore, we can opine that compound A is a terminal phenyl substituted alkene whose formula = C8H8 (Styrene)

The diagrammatic expression of the compound can be seen below.

However, in the presence of the palladium catalyst, the reduction of Compound A with 4 units of hydrogen produces Compound B: C8H16 (Ethylcyclohexane).

To make a 0.500 M solution, one could take 0.500 moles of solute and add Group of answer choices enough solvent to make 1.00 kg of solution. enough solvent to make 1.00 L of solution. 1.00 L of solvent. 1.00 kg of solvent.

Answers

Answer: The correct option is enough solvent to make 1.00 L of solution

Explanation:

A solution consists of solute and solvent. A solute is defined as the component present in a smaller proportion while the solvent is defined as the component that is present in a larger proportion.

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

[tex]Molarity=\frac{Moles}{Volume}[/tex] .......(1)

We are given:

Molarity of solution = 0.500 M

Moles of solute = 0.500 moles

Putting values in equation 1, we get:

[tex]0.500mol/L=\frac{0.500mol}{\text{Volume of solution}}\\\\\text{Volume of solution}=\frac{0.500mol}{0.500mol/L}=1.00L[/tex]

Hence, the correct option is enough solvent to make 1.00 L of solution

If 0.5 L of O2(g) reacts with H, to produce 1 L of H2O(g), what is the volume of
H2O(g) obtained from 1 L of O2(g)?
-
0.5 L
2.5 L
2 L
1.5 L

Answers

Answer:

2 L

Explanation:

We'll begin by writing the balanced equation for the reaction. This is given below:

2H₂ + O₂ —> 2H₂O

From the balanced equation above, we can see clearly that 1 L of O₂ reacted to 2 L of H₂O.

This implies that 2 L of H₂O can be obtained by the reaction of 1 L of O₂.

Thus, option 3 gives the correct answer to the question.

Please select the word from the list that best fits the definition

Include skin, the respiratory system, the circulatory system, and inflammation


A. antibody
B. antigen
C.Natural Defences
D.active immunity

Answers

Answer:

I choose D option because may be it's correct

I believe it is c

Explanation:

because if u think about it and also do some research you would see that the circulatory system is a strong part of your body which can help u through natural defences if this sounds weird it's all in research but if it ain't c dont blame me for ruining your life- lol but yeah I think its c

Given the balanced reaction: Zn + 2HCl → H2 + ZnCl2
If 5 grams of each reactant are available for the reaction and HCl is known
to be the limiting reactant, which of the following is correct?
O Both reactants will be completely used up.
O There will be excess of both reactants remaining.
O HCl will be completely used up while Zn will remain in excess.
O Zn will be completely used up while HCl will remain in excess.

Answers

Answer:

O HCl will be completely used up while Zn will remain in excess.

Explanation:

Zn + 2HCl → H₂ + ZnCl₂

In reactions involving two reactants, if one of them is the limiting reactant then the other one has to be the reactant in excess.

Meaning that in this case, the reaction will proceed until HCl is completely used up, and a certain amount of Zn will remain (thus being the reactant in excess).

a solution that contains a large amount of solute would be described as what

Answers

Answer:

A concentrated solution is one that has a relatively large amount of dissolved solute. A dilute solution is one that has a relatively small amount of dissolved solute.

A rod “X”, has a positive charge of 5. An otherwise identical rod, “Y”, has a negative charge of 12.
The rods are touched together and then separated.
a) When they touched, what particles moved between them?
b) Did the particles move from “X” to “Y” or from “Y” to “X”.

Answers

Answer:

a) electrons

b) from Y to X

Explanation:

positive protons are the cores of atoms in relative to electrons very, very heavy.

the outer electrons of atoms can move, under certain conditions, away from the atom, leaving it electrically unbalanced -> positively charged

there can also be a surplus of electrons on many surfaces, leading to a static negative charge. you know this when you are charged and you discharge with an object or another person, electrically balancing the two bodies charge.

electrons are also much smaller. they are the "things" to move, let it be trough the air or trough a wire, while the heavy protons will stay in place (unless the materials is melted of course, extreme heat brakes the bounds between atoms relatively well)

gress.
Newton's third law of motion
Is the following statement true or false?
When a large truck pushes a small car with a given force, the small car is applying an equal and opposite
force on the truck.
Choose 1 answer:
True
False

Answers

Answer:

true

Explanation:

the small car also has gravity making it heavy

At 258C, Kp 5 2.9 3 1023 for the reactionNH4OCONH21s2m 2NH31 g21 CO21 g2In an experiment carried out at 258C, a certain amount of NH4OCONH2 is placed in an evacuated rigid container and allowed to come to equilibrium. Calculate the total pressure in the container at equilibrium.

Answers

Answer:

0.27 atm

Explanation:

At 25ºC, Kp = 2.9 x 10⁻³ for the reaction NH₄OCONH₂(s) ⇌ 2 NH₃(g) + CO₂(g). In an experiment carried out at 25ºC, a certain amount of NH₄OCONH₂ is placed in an evacuated rigid container and allowed to come to equilibrium. Calculate the total pressure in the container at equilibrium.

Step 1: Make an ICE chart

Solid and liquids are ignored in ICE charts.

       NH₄OCONH₂(s) ⇌ 2 NH₃(g) + CO₂(g)

I                                            0             0

C                                        +2x           +x

E                                          2x             x

Step 2: Write the pressure equilibrium constant expression (Kp)

Kp = [NH₃]² × [CO₂]

Kp = (2x)² × x

2.9 × 10⁻³ = 4 x³

x = 0.090 atm

Step 3: Calculate the pressures at equilbrium

pNH₃ = 2x = 2(0.090 atm) = 0.18 atm

pCO₂ = x = 0.090 atm

The total pressure is:

P = 0.18 atm + 0.090 atm = 0.27 atm

Write the molecular formula for the compound that exhibits a molecular ion at M+ = 112.0499. Assume that C, H, N, and O might be present, and use the exact masses below:

Exact mass of carbon = 12.000
Exact mass of hydrogen = 1.0078
Exact mass of nitrogen = 14.003
Exact mass of oxygen = 15.995

The order of atoms should be carbon, then hydrogen, then the others in alphabetical order.

Answers

Answer:

C₆H₁₀NO

Explanation:

In order to arrive at a molecular formula we have to make some assumptions and they are

Assuming there is one ( 1 ) N and one ( 1 ) O that is present in the said molecule

Total mass =   29.998

next step: subtract the total mass from 112.0499 = 82.501

next : assume the presence of 6 carbon atoms in said molecule

Total mass =  6 * 12 = 72

Mass of Hydrogens = 82.501 - 72 = 10.501

∴ number of hydrogens = 10.501 / 1.0078  ≈ 10

Hence Total mass = 29.998 + 82.501  ≈ 112.0499

Finally Molecular formula = C₆H₁₀NO

An elementary step is defined as a chemical collision in a reaction mechanism. A collection of different types of collisions makes up the reaction mechanism, so elementary steps provide a molecular view of the overall reaction.

a. True
b. False

Answers

The answer is A. True
A. True is your answer hope this helps

the density of gold is 19.3 g/ml. if you had a cube made of pure gold that weighs 58.1 pounds what would be the lengh of a side of this cube

Answers

Answer:

11.1 cm

Explanation:

First we convert 58.1 pounds into grams:

58.1 lb * [tex]\frac{453.592g}{1lb}[/tex] = 26353.69 g

Then we calculate the volume of the gold cube, using the given density:

26353.69 g ÷ 19.3 g/mL = 1365.48 mL

1365.48 mL is equal to 1365.48 cm³.

With the volume of a cube we can calculate the side length:

Length = ∛(1365.48 cm³) = 11.1 cm

Increasing the temperature of a particular liquid from 298 K to 318 K causes its vapor pressure to double. What is the enthalpy of vaporization of this liquid

Answers

Answer:

27.3 kJ/mol

Explanation:

Step 1: Given data

Temperature 1 (T₁): 298 KVapor pressure 1 (P₁): P₁Temperature 2 (T₂): 318 KVapor pressure 2 (P₂): 2 P₁

Step 2: Calculate the enthalpy of vaporization of this liquid

We will use the Clausius–Clapeyron equation.

ln (P₂/P₁) = -ΔHvap/R × (1/T₂ - 1/T₁)

ln 2 = -ΔHvap/(8.314 J/K.mol) × (1/318 K - 1/298 K)

ΔHvap = 2.73 × 10⁴ J/mol = 27.3 kJ/mol

Elements beyond iron are not formed by a-particle capture. It is believed they are formed by neutron capture. Once the nucleus gets enough neutrons, one neutron converts to an electron and a proton. Show how you can make zinc from copper by neutron capture.

Answers

Answer: The equation is [tex]_{29}^{63}\textrm{Cu}\rightarrow _{30}^{63}\textrm{Zn}+_{-1}^0e[/tex]

Explanation:

Neutron capture is a process where a neutron is converted into a proton and an electron. The released particle is known as beta particle and it carries a charge of -1 units and has a mass of 0 units. It is also known as an electron. The general equation for this process is:

[tex]_Z^A\textrm{X}\rightarrow _{Z+1}^A\textrm{Y}+ _{-1}^0\e[/tex]

The nuclear equation for the formation of zinc via neutron capture of copper follows:

[tex]_{29}^{63}\textrm{Cu}\rightarrow _{30}^{63}\textrm{Zn}+_{-1}^0e[/tex]

The information code that an organism inherits can best be referred to as its -
O A genotype
B. territory
C. species
D. kingdom

Answers

Answer:

it will be no.A genotype

Which type of scientist would most likely investigate how to synthesize
materials found in plants?
O A. A geologist
O B. A biologist
O C. A chemist
OD. A physicist

Answers

Answer:

Biologist

Explanation:

Not sure, but I think that is right

A 250ml sample of sir at 373.15k is warmed at 473.15 at constant pressure. What is the volume of the air sample at the new temperature

Answers

Answer:

317 mL.

Explanation:

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

Initial volume (V₁) = 250 mL

Initial temperature (T₁) = 373.15 K

Final temperature (T₂) = 473.15 K

Pressure = Constant

Final volume (V₂) =?

The final volume of the air sample can be obtained by using the Charles' law equation as illustrated below:

V₁/T₁ = V₂/T₂

250 / 373.15 = V₂ / 473.15

Cross multiply

373.15 × V₂ = 250 × 473.15

373.15 × V₂ = 118287.5

Divide both side by 373.15

V₂ = 118287.5 / 373.15

V₂ = 317 mL

Therefore, the final volume of the air sample is 317 mL

What happens when you increase the pressure on the following
reaction
2X(g) + 3Y(g) --> 5Z(g) + heat

Answers

Answer:

When pressure increases, there is no effect on the reaction because volume is constant.

C8H18+O2=CO2+H2O. Balance this equation and identify the number H2O molecules formed when 6 molecules of C8H18 react with 75 molecules of oxygen

Answers

Answer: 54 molecules of water will be formed in the reaction.

Explanation:

A balanced chemical equation is one where all the individual atoms are equal on both sides of the reaction. It follows the law of conservation of mass.

For the given unbalanced chemical equation, the balanced equation follows:

[tex]2C_8H_{18}+25O_2\rightarrow 16CO_2+18H_2O[/tex]

We are given:

Molecules of [tex]C_8H_{18}[/tex] = 6

Molecules of [tex]O_2[/tex] = 75

By the stoichiometry of the reaction:

If 2 molecules of [tex]C_8H_{18}[/tex] produces 18 molecules of water

So, 6 molecules of [tex]C_8H_{18}[/tex] will produce = [tex]\frac{18}{2}\times 6=54[/tex] molecules of water

Hence, 54 molecules of water will be formed in the reaction.

Boric acid, B(OH)3, acts as an acid in water, but does not do so via ionization of a proton from boric acid. Use a balanced chemical equation to show why boric acid may be described as an acid in water.

Answers

Answer:

B(OH)₃ + H₂O = B(OH)₄⁻ + H⁺

Explanation:

Let's consider Arrhenius acid-base theory:

An acid is a substance that in aqueous media releases H⁺.A base is a substance that in aqueous media releases OH⁻.

Boric acid, B(OH)₃ reacts with water according to the following equation.

B(OH)₃ + H₂O = B(OH)₄⁻ + H⁺

As we can see, boric acid releases H⁺ in aqueous media. Thus, it is an acid.

The limiting reactant in a chemical reaction is the reactant __________ Select one: A. for which you have the lowest mass in grams. B. which has the lowest coefficient in the balanced equation. C. which has the lowest molar mass. D. which is left over after the reaction has gone to completion. E. None of the above.

Answers

Answer:

i think its A

A sample of carbon tetrachloride (CCl4) contains 3 moles of the substance. How many atoms are there in the sample?

Answers

Answer:

1.806 × 10²⁴ atoms

Explanation:

To obtain the number of atoms a substance contain, we have to multiply the number of moles in that substance (n) by Avogadro's number, which is 6.02 × 10²³.

According to this question, a sample of carbon tetrachloride (CCl4) contains 3 moles of the substance. The number of atoms in CCl4 is calculated thus:

number of atoms = 3 × 6.02 × 10²³

number of atoms = 18.06 × 10²³

number of atoms = 1.806 × 10²⁴ atoms.

1,500 grams is equal to:
1.5 kg
1.5L
1.5 cm
all of the above

Answers

1kg is 1,000 grams plus .5 is 1.5 kg

what climate zone is asia?

Answers

Answer:

The Tundra Climate

Explanation:

:) hope this helps

The answer is As the aggregate result of those various meteorological patterns, the following types of climate may be distinguished in Asia: the tundra climate (associated with the cold, treeless plains of the Arctic lowlands of Asia); the cold, sharply continental climate of eastern Siberia; the cold, moderately humid western

PLEASE HELP‼️‼️
A
B
C
D

Answers

C is your answer :) have a great day
I don’t actually know chemistry, I’m just going with the awnser above mine and saying it’s c
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