The diagram shows Niels Bohr’s model of an atom.


A small green circle labeled Proton is surrounded by 4 concentric circles. The space inside the first concentric circle is labeled N = 1; the space between the first and second circle is labeled N + = 2; between the second and third N = 3, and between the third and fourth N = 4. Oblong gray shapes labeled Electron appear on the second and third concentric circles.

What happens when the electron moves from the first energy level to the second energy level?
Energy is absorbed, and an emission line is produced.
Energy is released, and an emission line is produced.
Energy is absorbed by the atom.
Energy is lost from the atom.

C.heat the solution

Some Energy is released into the environment as heat

Explanation:

Answer:

49 g/L is the concentration of the acid

Explanation:

Firstly, we proceed to write the equation of reaction.

2NaOH + H2SO4 ——-> Na2SO4 + 2H2O

We can see that 1 mole of the base reacted with two moles of the acid.

kindly note that dm^3 is same as liter

Firstly, we need to get the concentration of the reacted sulphuric acid in g/L

we use the simple titration equation below;

CaVa/CbVb = Na/Nb

From the question;

Ca = ?

Va = 25 cm^3

Cb = 20 g/L

we convert this to concentration in mol/L

Mathematically, that is concentration in g/L divided by molar mass in g/mole

molar mass of NaOH = 40 g/mol

so we have; 20g/L / 40 = 0.5 mol/L

Vb = 50 cm^3

Na = 1

Nb = 2

Where C represents concentrations, V volumes and N , number of moles

Now, substitute the values;

Ca * 25/0.5 * 50 = 1/2

25Ca/25 = 0.5

So Ca = 0.5 mol/L

Now to get the concentration of H2SO4 in g/L

What we do is to multiply the concentration in mol/L by molar mass in g/mol

That would be 0.5 * 98 = 49 g/L

The concentration of the acid in grams per litre is 49g/L

From the question,

We are to determine concentration of the sodium hydroxide solution.

First, we will write a balanced chemical equation for the reaction.

The balanced chemical equation for the reaction is

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

This means,

2 moles of NaOH is required to completely neutralize 1 mole of H₂SO₄

From the formula

[tex]\frac{C_{A}V_{A} }{C_{B}V_{B} }=\frac{n_{A} }{n_{B} }[/tex]

Where

[tex]C_{A}[/tex] is the concentration of acid

[tex]C_{B}[/tex] is the concentration of base

[tex]V_{A}[/tex] is the volume of acid

[tex]V_{B}[/tex] is the volume of base

[tex]n_{A}[/tex] is the mole ratio of acid

[tex]n_{B}[/tex] is the mole ratio of base

From the question

[tex]V_{A}= 25 \ cm^{3}[/tex]

[tex]C_{B} = 20 \ g/dm^{3}[/tex]

Convert this to mol/dm³

Molar mass of NaOH = 40 g/mol

Using the formula

[tex]Concentration\ in \ mol/dm^{3} =\frac{Concentration\ in \ g/dm^{3}}{Molar\ mass}[/tex]

∴ Concentration of the NaOH in mol/dm³ = [tex]\frac{20}{40}[/tex]

Concentration of the NaOH in mol/dm³ = 0.5 mol/dm³

∴ [tex]C_{B} = 0.5 \ mol/dm^{3}[/tex]

and

[tex]V_{B} = 50 \ cm^{3}[/tex]

From the balanced chemical equation

[tex]n_{A} = 1[/tex]

[tex]n_{B} = 2[/tex]

Putting the parameters into the formula, we get

[tex]\frac{C_{A} \times 25}{0.5 \times 50}= \frac{1}{2}[/tex]

Now, this becomes

[tex]2 \times 25 \times C_{A}=0.5 \times 50 \times 1[/tex]

Then, we get

[tex]50 C_{A} = 25[/tex]

∴ [tex]C_{A} = \frac{25}{50}[/tex]

[tex]C_{A} = 0.5 \ mol/dm^{3} = 0.5 \ mol/L[/tex]

Now, we will determine the concentration in g/L

From the formula,

Concentration in g/L = Concentration in mol/L × Molar mass

From the question,

Molar mass of sulfuric acid = 98

∴ Concentration of the acid in g/L = 0.5 × 98

Concentration of the acid in g/L = 49 g/L

Hence, the concentration of the acid in grams per litre is 49g/L

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Answer:

X= -Y + 2/2     Y=-X + 3/2

Explanation:

I don't know how to simplify it anymore. You would get x=-y+3/2 and y=-x+3/2

Answer:

Explanation:

(-1/2,1)

Gases, liquids and solids are all made up of atoms, molecules, and/or ions, but the way the particles inside them differ.

In a gas, the molecules are spread wide apart and moves freely at high speeds

In a liquid, the more closer to each other and will vibrate or slip past each other

In a solid, the molecules are tightly packed, making no room for each other and harder to move. These molecules vibrate and jiggle but, don't move

Answer: SI prefixes are used to form decimal multiples and submultiples of SI units. They should be used to avoid very large or very small numeric values.

Explanation: ^^^

Answer:

Absolute Zero

Explanation:

at 0 Kelvin, nothing can move and entropy reaches 0

Answer:

absolute zero

Explanation:

Answer:

[tex]C_{9.042}H_{17.958}[/tex]

Explanation:

(This exercise has been written in Spanish and for that reason explanation will be held in such language)

Por la definición del Número de Avogadro, un mol del compuesto contiene [tex]6.022 \times 10^{23}[/tex] moléculas. La masa de un mol se determina mediante regla de tres simple:

[tex]x = \frac{6.022\times 10^{23}\,molecules}{1\,molecule} \times (2.1\times 10^{-22}\,g)[/tex]

[tex]x = 126.462\,g[/tex]

Las participaciones másicas del carbono y el hidrógeno son, respectivamente:

[tex]m_{C} = 0.858\cdot (126.462\,g)[/tex]

[tex]m_{C} = 108.504\,g[/tex]

[tex]m_{H} = 126.462\,g - 108.504\,g[/tex]

[tex]m_{H} = 17.958\,g[/tex]

Ahora, el número de moles de cada elemento es calculado a continuación:

[tex]n_{C} = \frac{108.504\,g}{12\,\frac{g}{mol} }[/tex]

[tex]n_{C} = 9.042\,mol[/tex]

[tex]n_{H} = \frac{17.958\,g}{1\,\frac{g}{mol} }[/tex]

[tex]n_{H} = 17.958\,mol[/tex]

La fórmula molecular del hidrocarburo es:

[tex]C_{9.042}H_{17.958}[/tex]

Answer:

Alcohol

Structure: Alcohols are organic molecules assembled from carbon (C), oxygen (O), and hydrogen (H) atoms.

Property: The Boiling Point of Alcohols. Alcohols generally have higher boiling points in comparison to other hydrocarbons having equal molecular masses.

Aldehyde

Structure: DescriptionAn aldehyde is a compound containing a functional group with the structure −CHO, consisting of a carbonyl centre.

Property: The polarity of the carbonyl group notably affects the physical properties of melting point and boiling point, solubility, and dipole moment.

Ketone

Structure: A ketone is a functional group with the structure RC(=O)R', where R and R' can be a variety of carbon-containing substituents.

Property: Ketones are soluble in water but their solubility decreases with increase in the length of the chain.

Fatty Acid

Structure: a fatty acid consists of a straight chain of an even number of carbon atoms, with hydrogen atoms along the length of the chain and at one end of the chain and a carboxyl group (―COOH) at the other end.

Property: Fatty acids are solid at room temperature, while unsaturated fatty acids are liquid.

Ether

Structure: a class of organic compounds characterized by an oxygen atom bonded to two alkyl or aryl groups.

Property: An ether molecule has a net dipole moment due to the polarity of C-O bonds.

The functional group associated with ethanol is -OH, the aldehyde is -COH, the ketone is -CO, the fatty acid is -COOH, and ether is ROR.

The functional groups have been the atoms that have different constituents and properties with respect to other groups.

The functional group associated with the following groups has been:

The functional group associated with ethanol is -OH, the aldehyde is -COH, the ketone is -CO, the fatty acid is -COOH, and ether is ROR.

For more information about the functional group, refer to the link:

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Answer:

they should have a number that can completely transfer and fill the other atom

Explanation:

example:

sodium(2.8.1)and Chlorine(2.8.7)the sodium will give chlorine the 1 valence electrobo so they both become stable(2.8)±and(2.8.8)–

magnesium(2.8.2)and oxygen(2.6)same way as above to abtain mg(2.8)±²and oxygen(2.8)–²

Answer:

2O L

Explanation:

The balanced chemical equation is 2NO+O  

2

​  

→2NO  

2

​  

Thus, 2 moles of NO will produce 2 moles of NO  

2

​  

.

Also, the volume is directly proportional to the number of moles.

Therefore, 20 L of NO will produce 20×  

2

2

​  

=20 L of NO  

2

​  

Answer:

Explanation:

Pv = n RT

P =7.65, T= 310K, for glucose n = moles= weight/molar mass= weight/180, R is gas constant

7.65* V =W/180 *0.0821 * 310

w/v= 7.65*180/0.0821*310 = 1377/25.45 = 54.10 =5.4%

Answer:

NO2

Explanation:

N = Nitrogen

O = Oxygen

Answer:

NO. 2.

is the answer

hopes this helps

Answer:

I think its D sorry if im wrong

Answer:i think its D

Explanation:

Answer:

It is the energy that is stored in bonds that hold particles together

Explanation:

Answer:

Explanation:

Average Atomic mass of any element =[ ∑ Abundance* mass of element] /100

                                                                = 10*20 +11*80 /100

                                                                = .........

Hope this helps you

A chemical  reaction involves the interaction of reactants. The substance X ,must be an acid and in this case is CH3COOH

In chemistry, a reaction is said to occur when substances interact in such a way that other new substances are formed.

Now let us look at the particular reaction; NaOH + X ----> NaCH3COO + H2O. The substance X must be an acid. Hence, the most likely susbstance is CH3COOH.

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Answer: 1.29 moles of ethylene glycol must be added to 1 kg of water to make a solution with a freezing point of -2.4°C. Molality of solution is 1.29 m.

Explanation:

Depression in freezing point is given by:

[tex]\Delta T_f=i\times K_f\times m[/tex]

[tex]\Delta T_f=T_f^0-T_f=(0-(-2.4))^0C=2.4^0C[/tex] = Depression in freezing point

i= vant hoff factor (for non electrolyte , i = 1)

[tex]K_f[/tex] = freezing point constant for water= [tex]1.86^0C/kgmol[/tex]

m= molality =[tex]\frac{\text{moles of solute}}{\text{weight of solvent in kg}}[/tex]

m= molality =[tex]\frac{x}{1kg}[/tex]

[tex]2.4^0C=1\times 1.86^0C/kgmol\times \frac{x}{1kg}[/tex]

[tex]x=1.29[/tex]

Molality = [tex]\frac{\text{moles of solute}}{\text {weight of solvent in kg}}=\frac{1.29mol}{1kg}=1.29m[/tex]

Thus 1.29 moles of ethylene glycol must be added to 1 kg of water to make a solution with a freezing point of -2.4°C. Molality of solution is 1.29 m.

Answer:

1) C (m=T f/Kf)

2) 2.4 C

3) 1.3 m

4) 1.3 moles

Explanation:

This is correct on ed

Answer:

147.222

Explanation:

It's a simple conversion.

Answer:

[tex]\large \boxed{1.615 \times 10^{25}\text{ molecules water}}[/tex]

Explanation:

You must calculate the mass of the water, convert it to moles, and then calculate the number of molecules.

1. Mass of water

[tex]\text{Mass } = \text{499.8 mL} \times \dfrac{\text{0.967 g}}{\text{1 mL}} = \text{483.3 g}[/tex]

2. Moles of water

[tex]\text{Moles of water} = \text{483.3 g water} \times \dfrac{\text{1 mol water}}{\text{18.02 g water}} = \text{26.82 mol water}[/tex]

3. Molecules of water

[tex]\text{No. of molecules} = \text{26.82 mol water} \times \dfrac{6.022 \times 10^{23}\text{ molecules water}}{\text{1 mol water}}\\\\= \mathbf{1.615 \times 10^{25}}\textbf{ molecules water}\\\text{The sample contains $\large \boxed{\mathbf{1.615 \times 10^{25}}\textbf{ molecules water}}$}[/tex]

The number of molecules of water  present in the bottle is 1.62×10²⁵ molecules.

We'll begin by calculating the mass of the water in the bottle.

Mass = Density × Volume

Mass of water = 0.967 × 499.8

Mass of water = 483.3066 g

Finally, we shall determine number of molecules of water in the bottle.

From Avogadro's hypothesis,

1 mole of water = 6.02×10²³ molecules

But,

1 mole of water = 18 g

Thus, we can say that:

18 g of water = 6.02×10²³ molecules

Therefore,

483.3066 g of water = (483.3066 × 6.02×10²³) / 18

483.3066 g of water = 1.62×10²⁵ molecules

Thus, the number of molecules of water in the bottle is 1.62×10²⁵ molecules.

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Answer:

Since most of the data scientist collect is quantitative, data tables and charts are usually used to organize the information • Graphs are created from data tables • hope that helps love!

Answer:

organic chemistry

because it is study of carbon containing substances

Organic chemistry is the branch of Chemistry where hydrocarbons are the compounds of carbon and hydrogen.

Organic chemistry is the study of the structure, properties, composition, reactions, and preparation of carbon-containing compounds.

Hydrocarbons Derivatives are compounds which are made up of hydrogen and carbon with specific functional groups attached to them.

Examples:- Aldehydes, ketones, carboxylic acids, alcohols, alkyl halides, ethers, amines etc.

Hence, organic chemistry is the branch of Chemistry where

hydrocarbons are the compounds of carbon and hydrogen.

Learn more about organic chemistry here:

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#SPJ2

Answer:

0.1715 atm

Explanation:

We use the Ideal gas equation to calculate this

Mathematically;

PV = nRT

rearranging, we have

P = nRT/V

from the question, we have

n = 0.002 moles

R = 0.082

T = 250 = 250 + 273 = 523 K

V = 500 ml = 500/1000 = 0.5 L

Plugging the values we have;

P = (0.002 * 0.082 * 523)/0.5

P = 0.1715 atm

[H+]=3.98x10^-9

[H+]=10^-pH=10^-8.4

[H+]=10^-11, base

[H+]=10^-pH=10^-11

A solution with a pH of more than 7 is basic.

Lemon juice because it is more acidic

pH of lemon juice: 2.5

pH of vinegar: 3.3

Since the pH of lemon juice is lower, it is more acidic and will be more effective at removing the basic deposits.

Answer:

Explanation:

2.1>1000

?>500

(500×2.1)÷1000=1.05moles

Mass= molesx molar mass

1.05×(56+32+(16×4))

1.05×152=159.6g

Answer:

Basis and basic​ are two different words.

In English, Basis is used as a noun while basic is used as an adjective. Basis term refers as the base or starting point of any discussion.

For example: Bread is a basic ingredient of cake.

                      On the basis of Mendel's hypothesis.

In chemistry, Basis set is used as a set of functions that represent the electronic wave function in the density-functional theory which forms an  algebraic equations that can be easily implemented on a computer.

While Basic term is used for substances that can accept a hydrogen ion (H+) from another substance and have pH above 7. such as sodium.

So, It is not important that both the terms, basis and basic change their English meaning if used in chemistry, they both can be used with English meaning in chemistry as well. Bases and basic,​ both the terms can be used as either English or Chemistry without affecting the meaning.

Answer:

The answer is animals

Explanation:

Plants and fungi have a cell wall, and although most bacteria lack a cell wall, the question is asking in which kingdom do ALL organisms lack a cell wall. Hope this helps.

Answer:Bacteria

Explanation: