Please a little help in this I will really appreciate it

Answer:

1. How many ATOMS of boron are present in 2.20 moles of boron trifluoride? atoms of boron.

2. How many MOLES of fluorine are present in  of boron trifluoride? moles of fluorine.​

Explanation:

The molecular formula of boron trifluoride is [tex]BF_3[/tex].

So, one mole of boron trifluoride has one mole of boron atoms.

1. The number of boron atoms in 2.20 moles of boron trifluoride is 2.20 moles.

The number of atoms in 2.20 moles of boron is:

One mole of boron has ---- [tex]6.023x10^2^3[/tex] atoms.

Then, 2.20 moles of boron has

-[tex]=2.20 mol. x 6.023 x 10^2^3 atoms /1 mol\\=13.25x10^2^3 atoms[/tex]

2. Calculate the number of moles of BF3 in 5.35*1022 molecules.

[tex](5.35x10^2^2 molecules/6.023x10^2^3)x 1mol\\=0.0888mol[/tex]

One mole of boron trifluoride has three moles of fluorine atoms.

Hence, 0.0888moles of BF3 has 3x0.0888mol of fluorine atoms.

=0.266mol of fluorine atoms.

1. Constellations are group of stars that form pattems in the night sky

2. Ursa Major, Cassiopeia, and Orion are some common constellations.

3. Stars are used to tell directions and time, predict weather, and to serve as birth sign.

Answer: Convex mirror is curved in the outward direction and concave mirror in the inward direction.

Explanation:

1. Car rear view mirror: It is a convex mirror which gives the indication of large field of view and it allows the driver to view the traffic behind the car.

2. Security: The reflective bulge surfaces of the convex mirrors reflect the light outwards and provides an expanded field of view of the entire view of shops and other places useful for security.

3. Street light reflectors: They use convex mirrors because they are able to spread the light over the wider area.

4. Shaving facial hair: Concave mirror is used in shaving facial hair. It gives a bigger view of face when it is at the position of pole and focal point of the mirror.

5. Car light: It uses concave mirror because of the converging power it can focus more light rays at a particular point.

Answer: The mass of NaCl required to make 140 grams of a 12% solution of NaCl in water is 17 g.

Explanation:

Given: Mass of solution = 140 g

Mass percent = 12%

Formula used to calculate grams of solute are as follows.

[tex]Grams of solute = \frac{grams of solution \times mass percent}{100 percent}[/tex]

Substitute the values into above formula as follows.

[tex]Grams of solute = \frac{grams of solution \times mass percent}{100 percent}\\= \frac{140 g \times 12 percent}{100 percent}\\= 16.8 g\\= 17 g[/tex]

Thus, we can conclude that the mass of NaCl required to make 140 grams of a 12% solution of NaCl in water is 17 g.

Considering the definition of percentage by mass, the correct answer is the third option: 17 grams of NaCl is required to make 140 grams of a 12% solution of NaCl in water.  

The Percentage Composition is a measure of the amount of mass that an element occupies in a compound and indicates the percentage by mass of each element that is part of a compound.

This is, the percentage by mass expresses the concentration and indicates the amount of mass of solute present in 100 grams of solution.

In other words, the percentage by mass of a component of the solution is defined as the ratio of the mass of the solute to the mass of the solution, expressed as a percentage.

The percentage by mass is calculated as the mass of the solute divided by the mass of the solution, the result of which is multiplied by 100 to give a percentage. This is:

[tex]percentage by mass=\frac{mass of solute}{mass of solution}x100[/tex]

In this case, you know:

Replacing:

[tex]12=\frac{mass of solute}{140 grams}x100[/tex]

Solving:

mass of solute= [tex]\frac{12 x 140 grams}{100}[/tex]

mass of solute= 16.8 grams ≅ 17 grams

Finally, the correct answer is the third option: 17 grams of NaCl is required to make 140 grams of a 12% solution of NaCl in water.

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Answer:

Wavelength = 0.049 m

Explanation:

Given that,

The frequency of a wave,[tex]f=6.1\times 10^9\ Hz[/tex]

We need to find the wavelength of the wave. We know that,

[tex]c=f\lambda\\\\\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{2.998 \times 10^8}{6.1\times 10^9}\\\\\lambda=0.049\ m[/tex]

So, the wavelength of the wave is 0.049 m.

Answer:

See explanation

Explanation:

First we must obtain the limiting reactant. The equation of the reaction is;

CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (g)

Number of moles of CH4= 28.6 g/16g/mol = 1.8 moles

Since the reaction is 1:1, 1.8 moles of CO2 was produced

Number of moles of O2 = 57.6 g/32 g/mol = 1.8 moles

2 moles of O2 produced 1 mole of CO2

1.8 moles of O2 produced 1.8 × 1/2 = 0.9 moles of CO2

Hence O2 is the limiting reactant

Mass of CO2 produced = 0.9 moles × 44 g/mol = 39.6 g

%yield = 32.1g/39.6 g × 100

%yield = 81.1%

According to the reaction equation;

2moles of O2 reacts with 1 mole of CH4

1.8 moles of O2 reacts with 1.8 × 1/2 =0.9 moles of CH4

Number of moles of CH4 left = 1.8 moles - 0.9 moles

Number of moles of CH4 left = 0.9 moles

Answer:

In West Africa, garri refers to the creamy granular flour obtained by processing the starchy tuberous roots of freshly harvested cassava. ... Flour foodstuffs mixed with cold or boiled water are a major part of the diet amongst the various ethnicities of Nigeria, Benin Republic, Togo, Ghana, Guinea, Cameroon and Liberia.

Explanation:

Answer:

Conditioned

Explanation:

Naturally, you do not slow down when you see a yellow light. That response is learned, therefore it is a conditioned response.

Answer:

A standard system of measurement is very important because it helps us from making mistakes at the moment of doing calculations and correctly working...

Answer:

A standard measurement system is important because it allows scientists to compare data and communicate with each other about their results. Metric System – is a measurement system based on the number 10.

Answer:

To determine the number of atoms of Boron that are present within 3.61 grams of Boron Trifluoride, it would be best to convert the grams to moles of the compound and then after that use the Avogadro's number to determine the number of molecules and then use the 1 to 3 ratio to determine the total number of Boron atoms.

Answer:

See explanation

Explanation:

In Bohr's theory, electrons are found in specific regions in space called orbits. These orbits are also called energy levels. An electron may move from one energy level to another by absorbing or emitting energy.

In the wave mechanical model, electrons are not found in a particular region in space according to Heisenberg's uncertainty principle.

We rather define a certain region in space where there is a high probability of locating the electron. This region in space where there is a high probability of locating the electron is called an orbital.

Hence, in the Bohr's model of the atom,electrons can surely be found in orbits while in the wave mechanical model, the orbital is a probability function that describes a region in space where an electron may be found.

Answer:

a. 1 cm^3 = 1 mL

explanation:

Answer:

bitter leaf soups

Explanation:

because it cures gems out our body system

Answer:

An ice cube melting is a physical change because melting doesn't change the composition of the element. Paper burning is a chemical change because combustion occurs. Bubbles forming in a soda does involve chemical changes. Hard-boiling an egg is a chemical change because the egg's composition changed.

Answer

Tq so much.

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Answer:

Thank you so much.

Answer:

If 1000. mL of water freezes, which of the following is a reasonable approximation for the volume of the resulting ice?

Group of answer choices

1000. mL

961 mL

1040 mL

Explanation:

Ice is fewer denser than water.

The reason is the volume occupied by the same mass of ice with water is more than the volume occupied by water. Ice has more empty space within it.

Due to this reason, ice floats on water.

When 1000ml of water freezes to ice then its volume is greater than water.

Among the given options the correct answer is 1040 mL .

Answer:

Heat is absorbed.

Explanation:

Endothermic reactions: Heat is absorbed.

When there is a change in the endothermic chemical so here heat is absorbed.

It is the type of the chemical reaction that absorbed the heat from the environment. The absorbed energy that gives the activation energy for the reaction to arise.

hence, When there is a change in the endothermic chemical so here heat is absorbed.

Therefore, the first option is correct.

Learn more about heat here: https://brainly.com/question/1488118

Answer:

a group of electrochemical cells that can be recharged

Answer:

He should ask an adult if they know what the solution is. if they dont, put it back and find a different cleaning solution to use

Answer:

+3·F

Explanation:

The number of objects in the given system = 2 objects

The charge on each object are; q₁ = -Q, q₂ = -Q

The force acting between the objects = +F

The distance between the objects = 2·d

The formula for the force acting between two charged particles is given as follows;

[tex]F=K \times \dfrac{q_{1} \times q_{2}}{r^{2}}[/tex]

Therefore, we get;

[tex]F=K \times \dfrac{-Q \times -Q}{(2\cdot d)^{2}} = K \times \dfrac{Q^2}{4 \cdot d^2}[/tex]

By tripling the charge, q₁, on the first object, we get;

q₂ = 3 × (-Q)

[tex]F_2=K \times \dfrac{-3 \cdot Q \times -Q}{(2\cdot d)^{2}} = K \times \dfrac{3 \cdot Q^2}{4 \cdot d^2} = 3 \times +F = +3\cdot F[/tex]

Therefore, the new force between them, F₂ = +3·F

Answer:

About 96 to 256 ATP molecules are produced.

Explanation:

About 96 to 256 ATP molecules may be synthesized in the full metabolism in oligosaccharide because one oligosaccharide molecule has 3 to 8 glucose atoms. About 30 to 32 ATP are produced from one glucose molecule so from three glucose molecule, 96 ATP produced whereas 256 ATP molecules are produced from 8 glucose molecules so we can say that About 96 to 256 ATP molecules from one oligosaccharide.

Answer:

[tex]10 {7}^{2} = [/tex]

Answer: Decomposition is the answer

Explanation: why because aluminium hydroxide would decomposes in the presence of heat and would form an oxide which is aluminium oxide and would also form water as a product.

HOPE THIS HELPS!!

Answer:

this is your answer i hope it will help you if this answer is right then folow meChromatography can be quantitatively found by the retention factor. Therefore, the important criterion to use chromatography for separating components of a mixture is the difference in solubility of the liquids.

(1) Seven electrons

1s² 2s²2p³

There are two electrons in the 2s subshell and three in the 2p subshell. The remaining two electrons are in the inner 1s subshell.

(2) 22 electrons

1s² 2s²2p⁶ 3s²3p⁶ 4s²3d²

There are two electrons in the 4s subshell and two in the 2p subshell. The remaining 18 electrons are in the inner subshells.

(3) 17 electrons

1s² 2s²2p⁶ 3s²3p⁵

There are two electrons in the 3s subshell and five in the 2p subshell. The remaining 10 electrons are in the inner subshells.

(4) n = 4, l = 2

(5) N=2 I=0 MI=0

(6) There can be two electrons in one orbital maximum. The s sublevel has just one orbital, so can contain 2 electrons max. The p sublevel has 3 orbitals, so can contain 6 electrons max. The d sublevel has 5 orbitals, so can contain 10 electrons max.

(7) n = 4 can hold up to 16 electrons

There are 4 sublevels; 42, 4p, 4d and 4f

4s (1 orbital), 4p (3 orbitals)

4d (5 orbitals), 4f (7 orbitals)

Maximum number of electrons in energy level: 16

s = 1 orbital

p = 3 orbitals

d = 5 orbitals

f = 7 orbitals

Add these up;

1 + 3 + 5 + 7 = 16

(8) 14 electrons If l = 3, the electrons are in an f subshell. The number of orbitals with a quantum number l is 2l + 1, so there are 2×3 + 1 = 7 f orbitals. Each orbital can hold two electrons, so the f subshell can hold 14 electrons.

sorry i didn't do the last two.. also sorry if some or none of these are correct, i tried my best

Explanation:

this is the reason why aluminium's boiling point is higher than that of sodium. sodium forms Na+ ions, therefore 1 electron is lost from each sodium atom, whereas aluminium forms Al3+ ions, so 3 electrons are lost for each Aluminum atom. The number of delocalised electrons therefore increases from sodium to aluminium, and charge density of the ions increases as the ionic charge increases and size decreases.

Answer:

no lo se yo hablo en español no en ingles

Answer:

ouch......it's kinda a practical question..

Answer: ?

Explanation: what was the answer?