Why are emission spectra referred to as the fingerprints of the elements?

Answer:

C. 70%

Explanation:

Atomic Mass of the silicon = 28 g.

Atomic mass of the Carbon = 12 g.

Total mass of the Silicon Carbide = 28 + 12

= 40 g.

Now, Using the formula.

% Composition = Mass of the silicon/Total mass of the compound × 100 %

= 28/40 × 100 %

= 70 %

Hence, % composition of the silicon in SiC is 70%

a) acid-neutral-base

How many acids are shown? 4

How many bases are shown? 7

What range seems to be missing? 5-6

A cabbage indicator will turn red in an acid solution, purple in a neutral solution, and green to yellow in basic solutions. To find out how many acids or bases are shown in a photo, count the number of solutions that have turned red (for acids) or green to yellow (for bases).

Unfortunately, without the specific photo referenced in the question, it's impossible to provide an exact order of the solutions. However, I can explain how to determine if a solution is an acid or base using a cabbage indicator. When a cabbage indicator is added to different solutions, it changes colors based on the pH level of the solution. In acidic solutions, the cabbage indicator turns red, while it turns green to yellow in basic solutions. The neutral solution will have a purple color.

To find out how many acids or bases are shown in the photo, you would count how many of the solutions turn red (for acids) or green to yellow (for bases).

https://brainly.com/question/31963334

#SPJ2

Answer:

worldwide burning of fossil fuels

Explanation:

The heavy usage of the fossil fuels as energy sources for the industry has resulted in much increased emissions of CO2 in the atmosphere. It all started around 200 years ago with the Industrial Revolution. In order for the machines to function, efficient energy sources were needed, and the best thing at that time for that was the coal. Through the burning, the coal manages to release enormous amounts of CO2 into the atmosphere. After some time, the oil was discovered as well, and it started to be heavily used as well, further increasing the CO2 emissions. As the technology has been developing more and more, the demand for the usage of the fossil fuels has been increasing constantly, so there's an ever growing CO2 emissions into the atmosphere.

I believe your answer would be the 3rd one

Answer:

[tex]Br_{4}Si[/tex] is written incorrectly

Explanation:

In a molecular formula, the central atom in it's lewis structure is written first followed by other bonded atoms.

The least electronegative atom (except H) is the central atom in a lewis structure.

In [tex]Br_{4}Si[/tex], Si is the least electronegative atom as Br has higher electronegativity than Si. Therefore Si is the central atom in lewis structure of [tex]Br_{4}Si[/tex]. So molecular formula of [tex]Br_{4}Si[/tex] should be written as [tex]SiBr_{4}[/tex].

In all other cases, the least electronegative atom have been written first.

So, [tex]Br_{4}Si[/tex] is written incorrectly.

Answer:

95.15%

Explanation:

To calculate the percent yield, we need the following formula:

[tex]\% yield=\dfrac{actual yield}{theoreticalyield}\times100\%[/tex]

Solving for the theoretical yied, you need to predict how much of the product will be produced if we USE up the given.

Our given is 224g of Fe and we to get the theoretical yield, we need to figure out how much product will Fe produce supposing that we use up all the reactant.

First thing we do is get the balance equation of this chemical reaction:

4Fe + 3O₂ → 2Fe₂O₃

We get the ratio between Fe and the the product, Fe₂O₃

[tex]\dfrac{4moles of Fe}{2molesofFe_{2}O_{3}}=\dfrac{2moles of Fe}{1moleofFe_{2}O_{3}}[/tex]

This basically means that we need 2 moles of Fe to produce 1 mole of Fe₂O₃. We'll use this later.

Now we let's use our given:

We need to first convert our given to moles. To do this, we need to determine how many grams there are of the reactant for every mole. We need to first get the atomic mass of the elements involved in the substance:

          Iron(1)      

Fe  =   55.845(1) = 55.845g/mole(1)

Then we use this to convert grams to moles

[tex]244g\times\dfrac{1mole}{55.845g}=4.369moles[/tex]

This means that there are 4.396moles of Fe in 244g of Fe.

This we will use to see how many moles of product we can produce given the moles of reactant by using the reactant:rproduct ratio.

[tex]4.369moles of Fe\times\dfrac{1moleofFe_{2}O_{3}}{2molesofFe}=2.185 moles of Fe_{2}O_{3}[/tex]

So given 4.693 moles of Fe we can produce 2.185 moles of Fe₂O₃

The next step is to get how many grams of product there are given our calculation. We do this again by getting how many grams of Fe₂O₃ there are in 1 mole.

               Fe(2)              O(3)    

Fe₂O₃=55.845(2)  +  15.999(3)

         = 111.69        +   47.997      =159.687g/mol

We then use this to solve for how many grams of product there are in 2.185 moles.

[tex]2.185moles\times\dfrac{159.687g}{1mole}=348.92g[/tex]

This is our theoretical yield 348.92g of Fe₂O₃.

We can finally use our percent yield equation. Our actual yield is given by the probelm, 332g of Fe₂O₃ and we solved for our theoretical yield which is 348.92g of Fe₂O₃. We plug this in our formula and solve.

[tex]\%yield=\dfrac{actual yield}{theoreticalyield}\times100\%[/tex]

[tex]\%yield=\dfrac{332gofFe_{2}O_{3}}{348gofFe_{2}O_{3}}\times100\%=95.15\%[/tex]

So the answer is 95.15%

Final answer:

pH is a measure of how acidic or basic a solution is, based on the hydrogen ion concentration. The pH scale ranges from 0 to 14, where values below 7 are acidic and above 7 are basic. It is calculated as the negative logarithm of the hydrogen ion concentration.

Explanation:

Understanding pH

What is pH? pH is a measure that indicates the acidity or basicity (alkalinity) of a solution. It is a scaled value ranging from 0 to 14 where:

A pH of 7 is considered neutral; neither acidic nor basic.

Values below 7 indicate an acidic solution with a higher concentration of hydrogen ions (H+).

Values above 7 indicate a basic solution with a lower concentration of hydrogen ions.

The pH is calculated as the negative, base-10 logarithm of the hydrogen ion concentration in the solution. A lower pH number means a higher concentration of hydrogen ions and therefore a more acidic solution. Conversely, a higher pH means a lower concentration of hydrogen ions and a more basic solution. The pH scale is a concise way to represent the hydrogen ion concentration, which varies markedly among different solutions and affects their properties.

Answer:

master, family member, family room

The best order of choices listed from best to worst is master bedroom, family member’s bedroom, family room.

The correct order of choices from best to worst is:

The master bedroom, being the primary bedroom, should be the best choice. The family member's bedroom is the next suitable option, and the family room is the least private space among the choices provided.

Answer:

The magnitude of the force decreases by a factor 4

Explanation:

The magnitude of the electrical force between a pair of charged objects is given by

[tex]F=k\frac{q_1 q_2}{r^2}[/tex]

where

k is the Coulomb's constant

q1, q2 are the charges of the two objects

r is the distance between the two objects

In this problem, the two objects are moved twice as far apart, so their distance becomes

r' = 2r

Substituting into the equation, we find the new force

[tex]F'=k\frac{q_1 q_2}{r'^2}=k\frac{q_1 q_2}{(2r)^2}=\frac{1}{4}(k\frac{q_1 q_2}{r^2})=\frac{1}{4}F[/tex]

The electrical force between two charged particles decreases when the distance between these particles is increased. If the distance is doubled, the force becomes a quarter of the original due to the inverse square law of Coulomb's Law.

The magnitude of the electrical force between two charged objects is governed by Coulomb's Law which states the force is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. Increasing the distance between the objects would cause a corresponding decrease in force. Specifically, if the distance between the pair of charged objects is doubled, the force will be reduced to one-fourth (1/4) of what it was initially as the relationship is based on an inverse square law.

In simpler words, if you double the distance, the force becomes weaker and reduces to a quarter of its original value.

https://brainly.com/question/20935307

#SPJ11

Answer:

2.4 kPa.

Explanation:

According to Dalton's law: the total pressure of an ideal gas mixture is equal to the sum of the partial pressures of the gases in the mixture.

Ptotal = P of O₂ + P of N₂ + P of CO₂.

where, Ptotal is the total pressure = 32.0 kPa,

P of O₂ is partial pressure of oxygen gas = 6.6 kPa,

P of N₂ is the partial pressure of nitrogen gas = 23.0 kPa,

P of CO₂ is the partial pressure of carbon dioxide gas = ??? kPa.

∵ Ptotal = P of O₂ + P of N₂ + P of CO₂.

∴ 32.0 kPa = 6.6 kPa + 23.0 kPa + P of CO₂.

∴ P of CO₂ = 32.0 kPa - (6.6 kPa + 23.0 kPa) = 2.4 kPa.

Answer:

Explanation:

1) Word equation (given)

2) Chemical formulae of the reactant and products:

The most common oxidation states of chlorine are -1, +1, +3, +5, +7.

The suffix ate in chlorate means that chlorine atom is with the third lowest oxidation state (counting only the positive states). So, this is +5.

The oxidation state of calcium is +2.

Hence, the chemical formula of calcium chlorate is Ca(ClO₃)₂

The suffix ide in chloride means that chlorine is with oxidation state -1. Again the oxidation state of calcium is +2.

Hence, the chemical formula of calcium chloride is CaCl₂

Oxygen gas is a diatomic molecule, so its chemical formula is O₂.

The symbols s and g (in parenthesis) indicate the solid and gas phases respectively.

3) Chemical equation:

That equation is not balanced becasue the number of O atoms in the reactant side and in the product side are different.

4) Balanced chemical equation:

Add a 3 as coefficient in front of O₂(g), in the product side to balance:

Verify that all the atoms are balanced:

Atom    Reactant side      Product side

Ca             1                           1

Cl              2                          2

O              3×2 = 6                2×3 = 6

Conclusion: the equation is balanced and the final answer is:

The decomposition of solid calcium chlorate into solid calcium chloride and oxygen gas is represented by the balanced chemical equation 2Ca(ClO3)2(s) → 2CaCl2(s) + 3O2(g).

The balanced chemical equation for the decomposition of solid calcium chlorate to form solid calcium chloride and oxygen gas is:

2Ca(ClO3)2(s) → 2CaCl2(s) + 3O2(g)

This reaction involves the breakdown of calcium chlorate, a chlorate compound, into calcium chloride, a chloride compound, and the release of oxygen gas. This type of reaction is known as a decomposition reaction, where a single compound breaks down to form two or more simpler substances.

https://brainly.com/question/28294176

#SPJ3

When you are discussing the concentration of solution, you are discussing how many particles there are in a given amount of solvent. You are comparing. If there is more solute in a beaker of solvent, then it is highly concentrated. If there is less solute in a beaker of the same amount of solvent, then it is less concentrated or more dilute. The terms diluted and concentrated are related to each other. These words are used to compare certain solutions to each other, since there is nothing like numbers, these words are relative to one another.

Final answer:

Discussing the concentration of a solution means specifying the exact amount of solute dissolved in a given amount of solvent. It can be expressed as a mass percentage, ppm, or ppb, and is important for understanding solution strength and stoichiometry in chemical reactions.

Explanation:

To discuss the concentration of a solution means to specify the amount of solute that is dissolved in a given volume or mass of solvent. Descriptive words like dilute or concentrated provide a general idea but actual measurements of concentration give precise meaning. For instance, a solution with a high concentration has a large amount of solute relative to the solvent. Conversely, a solution with a low concentration has a smaller amount of solute. People familiar with making instant coffee or lemonade inherently understand this concept; too much powder results in a strong flavor, whereas too little leaves the solution weak and watery.

Concentration can be quantified in several ways, such as mass percentage, parts per million (ppm), and parts per billion (ppb). A common method is by stating the ratio of the mass of the solute to the total mass of the solution. This is vital in chemistry, especially for controlling reactions and understanding the stoichiometry of reactants in solutions.

The longer the day, the solar radiation is absorbed and the higher the temperature is.

I hope you have a great rest of your day!

❤

I believe it’s C......

it should be c <3 lol hahahahaahaa

You would have to use the molarity of calcium hydroxide to find the moles of calcium hydroxide. Once you have moles, just convert using mole:mole ratio and find the grams of sodium hydroxide.

Answer:

1) Increasing the pressure          A) Shift to the left  

2) Removing hydrogen gas        B) Shift to the right    

3) Adding a catalyst                     C) No effect

Explanation:

1) Decreasing the pressure:

so, the right match is: A) Shift to the left.

2) Adding hydrogen gas:

so, the right match is: B) Shift to the right.

3) Adding a catalyst:

so, the right match is: B) No effect.

When a constraint is imposed on a reaction system in equilibrium, the equilibrium position will change in order to annull the constraint.

A reaction is said to have attained dynamic equilibrium when the rate of forward reaction is equal to the rate of reverse reaction. We know that when a constraint is imposed on a reaction system in equilibrium, the equilibrium position will change in order to annull the constraint.

Now the effect of the factors stated on the equilibrium position is matched  below;

Increasing the pressure ------ > Shift to the right

Removing hydrogen gas  -------> Shift to the left  

Adding a catalyst      ----------> No effect

Learn more about equilibrium position: https://brainly.com/question/14225536

Answer:

valence electrons

Explanation:

noble gases like argon or neon don't react easily with other elements because they have completely filled outer valence electron shell, but other elements react easily to try and have a noble gas structure.

Final answer:

Chemical reactivity is the propensity of an element to interact with others to form compounds, and it can be observed in reactions such as synthesis or combination reactions, where elements or compounds unite to form a new substance, following the principle that atoms are neither created nor destroyed.

Explanation:

The tendency of an element to react with other elements to produce compounds is termed reactivity, and it describes elements and compounds that are reactive and will readily react with many other substances. Reactive metals, for example, may form halide compounds with halogens or displace hydrogen from dilute acids.

When looking at chemical reactions, we must consider the starting substances that change. These are typically elements or compounds that combine in a reaction. This combination can yield a more complex compound. An example of this is a synthesis reaction, such as when sodium metal reacts with chlorine gas to form sodium chloride:

2 Na (s) + Cl2 (g) → 2 NaCl (s)

In a broader sense, chemical reactions adhere to the principle that atoms of different elements react with each other in fixed whole-number proportions to create compounds. During these reactions, atoms can separate and recombine to form new substances, but they are never created or destroyed.

Chemists have developed ways to categorize reactions to make predictions about which compounds will react and what products will be formed. Familiarity with basic types of reactions such as combination, decomposition, and displacement reactions is crucial. In the realm of combination reactions, one such reaction is the formation of carbon dioxide from the reaction of carbon monoxide with oxygen:

2CO (g) + O2 (g) → 2CO2 (g)

Answers:

Explanation:

See each choice:

a. Cl₂

b. K

c. Ag⁺

d. Zn²⁺

In terms of gaining and losing electrons, Cl2 and Ag+ (which gain electrons) are oxidizing agents. K, which loses an electron, is a reducing agent. Zn2+ also gaining electrons, acts also as an oxidizing agent.

In terms of tendencies to lose or gain electrons, a substance that tends to gain electrons and acts in oxidation reactions is called an oxidizing agent. Conversely, a substance that tends to lose electrons and acts in reduction reactions is known as a reducing agent.

Looking at the substances in question: a. Cl2 tends to gain electrons and hence would act as an oxidizing agent. b. K tends to lose an electron, and thus it would be a reducing agent. The c. Ag+ ion would gain an electron to become neutrally charged Ag, making it an oxidizing agent. Lastly, d. Zn2+ can also gain electrons and become neutral, making it an oxidizing agent as well.

https://brainly.com/question/30068396

#SPJ3

object in motion tends to be in motion unless acted upon by an external force

Answer:

The answer is A) objects in motion tend to stay in motion unless acted upon by an outside force

Explanation:

Newton's laws of motion are three laws that describe the relationship between forces acting on an object and the motion of that object. Newton's first law of motion states that an object that is at rest or in uniform motion tends to stay at rest or in uniform motion, respectively, until acted upon by an outside force.

Answer:

1.625 mol.

Explanation:

where, P is the pressure of the gas in atm.

V is the volume of the gas in L.

n is the no. of moles of the gas in mol.

R is the general gas constant.

T is the temperature of the gas in K.

n₂V₁ = n₁V₂

n₁ = 1.05 mole, V₁ = 5.17 L.

n₂ = ??? mole, V₂ = 8.0 L.

∴ n₂ = n₁V₂/n₂ = (1.05 mole)(8.0 L)/(5.17 L) = 1.625 mol.

The toy now contains 1.62 mol

#platofam

Answer:

15 kPa.

Explanation:

Ptotal = P1 + P2 + … + Pn.

∴ Ptotal = P of oxygen + P of nitrogen + P of hydrogen.

∴ P of hydrogen = P total - (P of oxygen + P of nitrogen) = 85 kPa - (20 kPa + 50 kPa) = 15 kPa.

Answer:

Explanation:

1) Balanced chemical equation (given):

2) Mole ratios:

3) Calculate the number of moles of reactant (H₂0):

4) Set a proportion using the mole ratio  O₂ to H₂O and the actual number of moles of H₂O:

5) Convert 2.36 moles O₂ to grams:

Answer:

37.87 g of oxygen can be produced from the 42.6 grams of H2O

Explanation:

From the question, the following equation shows the decomposition of gaseous water

2H₂O(g) ⇒ 2H₂(g) + O₂(g)

where atomic mass of hydrogen is 1 g/mol and atomic mass of oxygen is 16 g/mol

The molar mass of 2H₂O is;

2[(2 ×1) + (16 × 1)]

2(2+16) =  36 g

The molar mass of O₂ is;

2 × 16 = 32 g

Hence, it can be deduced that 36 g of water produced 32 g of oxygen, hence 42.6g of water will produce how many grams of oxygen (represented as X)

∴ 36 ⇒ 32

42.6 ⇒ X

X = 42.6 × 32/36

X = 37.87 g

Answer:

Diamond and graphite are allotropes of carbon.

Explanation:

Diamond has a close packed crystal structure which is responsible for its extreme hardness. In it, each carbon atom is sp³ hybridised and bonded to four other carbon atoms in a tetrahedral arrangement. Diamond has a hardness of 10 on mohs scale with a cubic crystal form.

Note: allotropes of an element have different molecular structure.

Graphite on the other hand is made up of layers of hexagonal structure that are weakly bonded by van-der-waals forces. This layered arrangement explains its softness/slippery feeling and hence it is used as a lubricant. In each layer, each carbon atom is sp² hybridised and bonded to three other carbon atoms in a trigonal planar arrangement.

The presence of [tex]\pi[/tex] electrons in the layers accounts for its ability to conduct electricity.

Answer:

Explanation:

NO₂ and N₂O₄ undergo the following equilibrium reaction:

That is a reversible reaction, i.e. there are two simultaneous reactions: the direct or forward reaction and the reverse reaction:

At the beginning, only NO₂(g) is in the sealed container. The NO₂ concentration is maximum, and the rate of the forward reaction is maximum.

As the reaction progresses, the concentration of NO₂ diminishes, and, consequently, the rate of the forward reaction decreases.

As soon as the N₂O₄ appears, the reverse reaction starts. At the beginning the rate is low, but as the N₂O₄ concentration increases the rate of the reverse reaction increases.

When both forward and reverse rates become equal the equilibrium has been reached. This is what is called a dynamical equilibrium.

Then, as per the choices, you have that, at equilibrium:

A) No N₂O₄ is present:

B) No chemical reactions are occurring.

C) The rates of the forward and reverse reactions are equal.

D) The maximum number of molecules has been reached.

The correct answer is "On a protein molecule, side chains of amino acids affect only the primary structure." If this is correct and was helpful could you mark me as brainlist? Thanks!

The amino acids side chain forms the basis for the conformation of peptide and affects the primary and secondary structure. Thus, option B is correct.

Proteins are the biomolecules composed of the amino acid chain bond with the peptide bond. The amino acids are composed of amino and carboxyl terminal, with a side chain determining the polarity.

The side chain forms the hydrogen bond and other type of bond in the peptide chain, and thereby governs the primary and the secondary structure of the protein. Thus, option B is correct.

Learn more about protein, here:

https://brainly.com/question/17095120

#SPJ2

Answer:

B. Poisonous substances that occur naturally or are accidentally added during food handling.

Explanation:

Chemical hazards are poisonous substances that occur naturally or are accidentally added during food handling. They can cause foodborne illnesses and include toxins produced by bacteria or fungi, pesticides, heavy metals, and other harmful chemicals.

Chemical hazards are defined as poisonous substances that occur naturally or are accidentally added during food handling. These hazards can include toxins produced by bacteria or fungi, pesticides, heavy metals, and other harmful chemicals. When these substances contaminate food and are ingested, they can cause foodborne illnesses. For example, aflatoxins are toxic and carcinogenic compounds released by fungi that can contaminate nuts and grains.

Learn more about Chemical hazards here:

https://brainly.com/question/3811598

#SPJ6

Answer:

option D = 204 Pa

Explanation:

Given data:

Weight of book = 12 N

Area of book =  0.21 m × 0.28 m = 0.0058 m²

Pressure of book = ?

Solution:

formula

pressure = force / area

P = f/ A

now we will put the values in formula,

P = 12 N/ 0.0058  m²

P= 204 Nm⁻²      ( Nm⁻²= Pa)

P = 204 Pa

The correct Answer is option (D). The pressure exerted by the book is approximately 204 Pa.

To find the pressure exerted by the book, we can use the formula for pressure:

[tex]\[ \text{Pressure} = \frac{\text{Force}}{\text{Area}} \][/tex]

First, calculate the area of the back cover:

[tex]\[ \text{Area} = \text{length} \times \text{width} \][/tex]

[tex]\[ \text{Area} = 0.21 \, \text{m} \times 0.28 \, \text{m} \][/tex]

[tex]\[ \text{Area} = 0.0588 \, \text{m}^2 \][/tex]

Now, calculate the pressure:

[tex]\[ \text{Pressure} = \frac{12 \, \text{N}}{0.0588 \, \text{m}^2} \][/tex]

[tex]\[ \text{Pressure} \approx 204.08 \, \text{Pa} \][/tex]

Rounding to the nearest whole number, the pressure exerted by the book is approximately 204 Pa.

Answer:

introducing a radioactive tracer into a sample of pesticide

Explanation:

introducing a radioactive tracer into a sample of pesticide

The heat absorbed in Trial 1 is about 3344 Joules greater than the heat absorbed in Trial 2.

The heat absorbed in an experiment is calculated using the formula Q = mcΔT, where 'Q' is the heat absorbed, 'm' is the mass of the substance, 'c' is the specific heat capacity of the substance, and 'ΔT' is the change in temperature. Here, the specific heat capacity of water 'c' is approximately 4.18 J/(g*C).

In Trial 1, we have: ΔT = 40.0 - 0 = 40°, and with mass 30.0 g, the heat absorbed (Q1) = mcΔT = 30.0g * 4.18 J/(g*C) * 40°C = 5016 J.

In Trial 2, we have: ΔT = 40.0 - 30.0 = 10°, and with mass 40.0 g, the heat absorbed (Q2) = mcΔT = 40.0g * 4.18 J/(g*C) * 10°C = 1672 J.

Therefore, the heat absorbed in Trial 1 is about 5016 - 1672 = 3344 J greater than the heat absorbed in Trial 2.

https://brainly.com/question/12943685

#SPJ12

Final answer:

The correct answer to the question is B. The atoms of the reactants combine to form a new substance, and in the case of hydrogen and oxygen gases, they react to form liquid hydrogen peroxide with different chemical properties.

Explanation:

When hydrogen gas and oxygen gas react to form liquid hydrogen peroxide, the atoms of the reactants combine to form a new substance. This is because a chemical reaction involves the rearrangement of atoms to produce new substances with different chemical properties.

The correct statement about this reaction is: B. The atoms of the reactants combine to form a new substance. In a chemical reaction such as this, the physical and chemical properties of the products are typically different from those of the reactants.

An example of a simple chemical reaction is the decomposition of hydrogen peroxide into water and oxygen.

This reaction can be represented by the balanced equation 2H₂O₂ (hydrogen peroxide) → 2H₂O (water) + O₂ (oxygen), showing that hydrogen peroxide and water are compounds composed of more than one type of element, while molecular oxygen is a homonuclear molecule but not a compound

It is B. What I found is when water freezes it's entropy decrease. If water freezing that means the temperature is decreasing and that is B.