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Correct answer=

gold is an element, it has a symbol of An

Hope it helped

Gold is an element, not a compound or a mixture. It is represented on the periodic table by the symbol Au and cannot be broken down into a simpler substance.

Gold is an element, not a compound or a mixture. It's one of the 118 known chemical elements, and it's represented on the periodic table by the symbol Au (from the Latin 'aurum'). As an element, gold consists of only one type of atom and cannot be broken down into a simpler substance. It differs from a compound, which is formed from two or more elements bonded together, and a mixture, where you can physically separate the individual components that make it up.

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According to Charles' Law the volume of an ideal gas is directly proportional to its absolute temperature in Kelvin keeping the pressure constant.

V∝ T, P  is constant  

where V, T and P are volume, temperature and pressure

[tex]\frac{V1}{T1 }[/tex] = [tex]\frac{V2}{T2}[/tex]

where V₁, T₁, V₂ and T₂ are initial volume, initial temperature, final volume and final temperature.  

Answer is: enthalpy is 155.65 kJ.

Reaction 1: N₂(g) + O₂(g) → 2NO(g); ΔrH₁ = 180.7 kJ.

Reaction 2: 2NO(g) + O₂(g) → 2NO₂(g); ΔrH₂ = -113.1 kJ.

Reaction 3: 2N₂O → 2N₂(g) + O₂(g); ∆rH₃ = -163.2 kJ.

Reaction 4: N₂O(g) + NO₂(g) → 3NO(g); ΔrH₄ = ?.

Using Hess's law reaction number 4 is sum of reaction number 1 and half of reaction number 3 minus half of the reaction number 2.

ΔrH₄ = ΔrH₁ + 1/2ΔrH₃ - 1/2ΔrH₂.

ΔrH₄ = 180.7 kJ + 1/2 · (-163.2 kJ) - 1/2 · (-113.1 kJ).

ΔrH₄ = 155.65 kJ.

Hess's law states that the enthalpy change in the chemical reaction is same, whether the reaction takes place in one or several steps. For the given equation, the enthalpy change of overall reaction is 155. 65 kJ.

[tex]\begin{aligned}\text{N}_2(\text{g})2\text{NO}(\text{g})+\text{O}_2(\text{g})\text{O}_2(\text{g})2\text{N}_2\text{O}(\text{g})\rightarrow2\text{NO}(\text{g}),2\text{NO}_2(\text{g}),2\text{N}_2(\text{g})+\text{O}_2(\text{g})\end{aligned}[/tex]

Given that,

1. The enthalpy change for the reaction between nitrogen and oxygen to form nitrogen oxide is:

2. The enthalpy change in the reaction between nitrogen oxide and oxygen to form nitrogen dioxide will be:

3.  The enthalpy change in breakdown of nitrous oxide to form nitrogen and oxygen:

4. The reaction between nitrous oxide and nitrogen dioxide will from nitrogen oxide as:

Using Hess's law on the fourth reaction, we get sum of first reaction and halved the enthalpy change of second and third reaction.

[tex]\begin{aligned}\Delta\text{rH}_4&=\Delta\text{rH}_1+\frac{1}{2}\Delta\text{rH}_3-\frac{1}{2}\Delta\text{rH}_2\\&=180.7\text{kJ}+\frac{1}{2}\times(-163.2\text{kJ})-\frac{1}{2}\times(-113.1\text{kJ})\\&=155.65\text{kJ}\end{aligned}[/tex]

Therefore, the enthalpy change for the equation will be 155.65 kJ.

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There are 0.400 mol Br₂ in the sample..

Mass of Br₂ = 20.5 mL Br₂ × 3.12 g Br₂/1 mL Br₂ = 63.96 g Br₂.

Moles of Br₂ = 63.96 g Br₂ × (1 mol Br₂/159.81 mol Br₂) = 0.400 mol Br₂

The 20.5 ml of bromine sample has been consisted of 0.4 mol.

Density can be defined as the mass of an element per unit volume. The density (D) can be expressed as:

[tex]D=\dfrac{M}{V}[/tex]

Where, m has been the mass of the compound

V has been the volume of the compound.

The given Bromine has:

[tex]D=3.12\;\text {g/ml}\\V=20.5\;\rm ml[/tex]

The mass of bromine has been calculated by substituting the values as:

[tex]3.12=\dfrac{m}{20.5}\\\\m=3.12\;\times\;20.5\;\text g\\\\m=63.96\;\text g[/tex]

The mass of bromine sample has been 63.96 g. The moles of the sample has been calculated as:

[tex]M=\dfrac{m}{mwt}[/tex]

Where, mass of the substance, [tex]m=63.96\;\text g[/tex]

Molecular weight of the substance, [tex]mwt=159.81\;\text{g/mol}[/tex]

Substituting the values for calculating moles (M) as:

[tex]M=\dfrac{63.96}{159.81}\;\text{mol}\\\\M= 0.4\;\text{mol}[/tex]

The number of moles of [tex]\rm Br_2[/tex] present in 20.5 ml has been 0.4 mol.

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Explanation: Genuine diamonds and imitation diamonds are different in terms of their strengths.

Strength is directly related to the density of the molecule.

High density means the molecule is hard as there will be no voids and the particles are closer to each other.

Lower density means that the molecule is soft because there will be voids present and the particles will be away from each other.

Genuine diamonds are hard in nature and hence they have high density while imitation diamonds can be broken down easily and hence they have has lower density.

The law of conservation of mass states that in any reaction mass is neither created nor lost it has to remain constant in a system.

In this case, when the reaction setup was done in normal way the mass was  lost in surrounding was not considered nor being calculated; whereas when the reaction was studied in a closed system where the gas was collected after the reaction the mass changes was noted down which helped to prove the point of law of conservation of mass and energy.

One can consider an example of soda can where the carbonated drink contains pressurized carbon dioxide gas. when opened the gas bubbles gets lost into the surroundings and we don't measure the mass changes. Instead if the soda can was opened in such a way where the gas evolved was measured then the mass changed would remain the same.

The discrepancy in mass during a normal setup versus a gas collection setup in a chemical reaction is due to the escape of gaseous products in the former, while the latter contains gases ensuring mass is conserved in accordance with the law of conservation of mass.

The phenomenon you are describing is related to the law of conservation of mass, which states that mass cannot be created or destroyed in a chemical reaction. When you observed a loss of mass in the normal setup, it's likely due to the escape of gas which was not contained. However, in the gas collection setup, no mass is lost because the gases produced are collected and their mass is taken into account, ensuring that the total mass remains the same, which adheres to the conservation of mass.

During chemical reactions, the total mass should always remain constant, as mass is conserved. If there is a difference in mass, as in the loss of -0.1834 g, it usually indicates that a gaseous product has escaped into the atmosphere and was not measured. In contrast, reactions like nuclear fusion and fission create such a vast amount of energy that there may be a measurable decrease in mass since some matter is converted into energy following Einstein's equation, E = mc², though this is not typically observable in chemical reactions.

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If they are moving on a plane, the bowling ball would be moving faster if applied the same amount of force as the golf ball.

This is because the bowling ball has a greater mass, and therefore greater kinetic energy.

The greater the kinetic energy, the faster the object will move.

Hope this helps and have a nice day! :)

the first and second answers i hope this helps :3

The density of urine decreases when a diabetic secretes too much sugar.

When there is excess sugar in the blood, the kidneys release extra water.

The result is a more dilute and therefore less dense urine.

The urine from a non-diabetic person usually has a density of 1.010 g/mL to 1.025 g/mL.

The urine from a diabetic person often has a density less than 1.008 g/mL.

The PROTON (option D) is the positively charged sub-atomic particle in the nucleus.

Answer:

D) proton

Explanation:

The electron is not found in the nucleus. Neurons are not sub-atomic particles. The nucleus is made up of the two particles. The neutral, or no-charge, neutron and the positively charged proton.

Answer:- d. London dispersion

Explanations:- Carbon dioxide structure is given below:

                 O=C=O

It has two polar C=O bonds but even then it is non polar molecule as it's linear and the dipole moment of one C=O bond is canceled by it's opposite C=O bond.

being non polar, the only attraction forces present in it are London dispersion forces.

Answer:

d. London dispersion

Carbon dioxide is derived from the reaction between Carbon and Oxygen and the structure is as shown  below:

                O=C=O

The only intermolecular force found in carbon dioxide is the London dispersion forces and they are forces which are caused by electron movement which forms dipoles.

Carbondioxide has two polar C=O bonds in which the dipoles are cancelled out thereby making it a non polar compound. This non-polarity is what makes the only force present to be the London dispersion forces and can also be regarded as the strongest intermoelcular bond found in the compound (CO₂)

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Given, weight of the woman = 55 kg

For the first 10 kg, fluid required is 100 mL/kg

So for the first 10 kg volume of fluid required is 100 ml/kg  x 10 kg = 1000 ml = 1 L

For the second 10 kg, fluid required is 50 mL/kg

So for the second 10 kg volume of fluid required is 50 ml/kg x 10 kg = 500 ml = 0.5 L

For the remaining (55 kg - 20 kg ) or 35 kg, fluid required is 20mL/kg

Now for the the remaining 35 kg  volume of fluid required is 20 ml/kg x 35 kg = 700 ml = 0.7 L

The total volume of fluid per day required by a 55 kg woman = 1L + 0.5L + 0.7L = 2.2 L

The volume of fluid per day needed by a 55kg woman, based on the given guide to fluid requirements, is 1000mL for the first 10kg, 500mL for the next 10kg, and 700mL for the remaining weight, totaling 2200mL or 2.2 liters per day when rounded to two significant figures.

To calculate the volume of fluid per day needed by a 55kg woman based on the rough guide to fluid requirements, we use the following method:

For the first 10kg of body weight: 100mL/kg.

For the next 10kg of body weight: 50mL/kg.

For the remaining weight over 20kg: 20mL/kg.

So for a 55kg woman:

For the first 10kg: 10kg x 100mL/kg = 1000mL

For the next 10kg: 10kg x 50mL/kg = 500mL

For the remaining 35kg: 35kg x 20mL/kg = 700mL

Therefore, the total fluid requirement is 1000mL + 500mL + 700mL = 2200mL, which rounded to two significant figures is 2200mL or 2.2 liters per day.

Left Panel

The trick is to look at the protons, all other things being equal. The yellow spheres are neutrons we are led to believe. All the diagrams show the same number of electrons(2), so there is no help there.

The upper left

The upper right

The Lower left

All have 2 protons and 2 electrons. <<<< Answer Read the 3 lines above.  

The center one has only 1 proton And the lower right has 3. Both of them are wrong.

Right Panel

You have answered this one correctly

When more heat is removed from the reaction, the rate of reaction slows down to counteract the heat loss. This can be controlled by changing the temperature or using a catalyst.

When more heat is removed from the reaction between zinc and hydrogen chloride, the rate of the reaction slows down to counteract the heat loss. This is because the reaction is exothermic, meaning it releases heat as a product. By slowing down the reaction rate, less heat is produced, helping to maintain equilibrium in the system.

One way the rate of reaction can be controlled is by changing the temperature of the system. When heat is removed, the temperature decreases, which decreases the kinetic energy of the reactant molecules. As a result, the frequency of successful collisions between reactant molecules decreases, slowing down the overall rate of the reaction.

Another way the rate of reaction can be controlled is by using a catalyst. A catalyst is a substance that speeds up the rate of a reaction without being consumed in the process. By providing an alternative pathway for the reaction to occur, a catalyst can help overcome the activation energy barrier, allowing the reaction to proceed at a faster rate.

We multiply the two numbers 2.5 and 1200 because thats the distance you went every hour and it equals 3000km

The study of numbers is called mathematics.

The correct answer is 3000km.

All the data is given in the question, the data is as follows:-

Placed all the values in the formula. the solution is as follows:-

[tex]D =S*T\\= 1200*2.5\\=3000km[/tex]

Hence, the correct answer is 3000km.

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There are approximately 8.7319 × 10²³ aluminum atoms in 1.45 mol of pure aluminum, calculated by multiplying the moles of aluminum by Avogadro's number.

To determine the number of atoms in 1.45 mol of pure aluminum (Al), we use Avogadro's number, which states that one mole of any substance contains 6.022 × 10²³ atoms.

The calculation is as follows:

Identify the amount in moles: 1.45 mol of Al.

Multiply the amount in moles by Avogadro's number: 1.45 mol  × 6.022 × 10²³ atoms/mol.

Perform the multiplication to find the total number of atoms: 1.45 × 6.022 × 10²³ = 8.7319 × 10²³ atoms of Al.

The SI defining constant Avogadro constant, often known as NA or L, has a precise value of 6.02214076×10²³ mol⁻¹. It serves as a normalisation factor for the amount of substance in a sample and is defined as the number of constituent particles per mole.

Therefore, there are approximately 8.7319 × 10²³ aluminum atoms in 1.45 mol of pure Al.

If a yes or no question, Yes

Physical properties are used to observe and describe matter. Physical properties can be observed or measured without changing the composition of matter. These are properties such as mass, weight, volume, and density.

Yeah basically, you just have to multiply the protons (29) and the number of atoms of copper (3) together. So, 29 times 3 is equal to 87.

The density is 0.515 g/cm³.

Mass = 22.91 g

Volume = 66.8 mL – 22.3 mL = 44.5 mL = 44.5 cm³

Density = mass/volume = 22.91 g/44.5 cm³ = 0.515 g/cm³

The planet forms, it is massive enough that it collects other objects that come near it and that's why they CAN have so many moons.

Gas giants dont have to stay so far from their sun. ... In our solar system, the outer planets vacuumed up all the available materials from Jupiter on out.

Ca = 40.1  

2 F = 38.0  

--------------  

78.1  

% F = 38.0/78.1  

Now you can calculate mass of F  

0.487 ( 255 g ) = 124 g F

Final answer:

To find the mass of fluorine in the sample, subtract the mass of chromium from the total mass of the sample. In a 36.01 g sample of CrF₃ with 18.83 g of Cr, there are 17.18 grams of fluorine.

Explanation:

The student asks how many grams of fluorine (F) are in a 36.01 g sample of chromium (III) fluoride (CrF₃) if there are 18.83 g of chromium (Cr) in the sample. To answer this, we conduct a mass difference calculation.

First, we subtract the mass of chromium (Cr) from the total mass of the sample to determine the mass of fluorine present:

Therefore, there are 17.18 grams of fluorine in the 36.01 g sample of CrF₃.

You must use 134 g O₂ to produce 118 g H₂O.

[tex]\%\text{ yield} = \frac{\text{actual yield}}{\text{theoretical yield}} \times 100 \%[/tex]

[tex]\text{Theoretical yield} = \text{Actual yield}\times \frac{100\%}{\%\text{ yield}} = \text{118 g }\times \frac{100 \%}{78.2 \%} = \text{150.9 g}[/tex]

M_r:          32.00    18.02  

         2H₂ + O₂ ⟶ 2H₂O

Moles of H₂O = 150.9 g H₂O × (1 mol H₂O/18.02 g H₂O) = 8.374 mol H₂O

Moles of O₂ = 8.374 mol H₂O × (1 mol O₂/2 mol H₂O) = 4.187 mol O₂

Mass of O₂ = 4.1877 mol O₂ × (32.00 g O₂/1 mol O₂) = 134 g O₂

Graphene is a semimetal with small overlap between the valence and the conduction bands. It is an allotrope of carbon consisting of a single layer of carbon atoms arranged in a hexagonal lattice (figure 1).It is the basic structural element of many other allotropes of carbon, such as graphite, diamond, charcoal, carbon nanotubes and fullerenes.

Graphene Carbon along metal:

Metal oxides such as TiO2 and ZnO are large-band-gap  semiconductors, and they are photocatalytically active under  UV irradiation. These oxides are capable of interacting with  graphene oxide via carboxylic acid functional groups. Thus, mixing of two suspensions of GO and TiO2 or ZnO  results in the binding of oxide particles to graphene oxide flakes. These particles remain suspended in suspension,  minimizing any aggregation effects.

Graphene Oxide-Metal Nanoparticle Composites

Reduced  graphene oxide serves as a support material to stabilize  metal nanoparticles. For example, the synthesis of silver and  gold nanoparticles stabilized by graphene oxide sheets has  been reported by several research groups.These  composites have also been assembled as ultrathin films using  a layer-by-layer self-assembly technique.30 The procedure to  make these composites consists of mixing of GO and a metal  salt solution (AgNO3, HAuCl4, or H2PtCl6) and adding a dilute  borohydride solution. The chemical reduction process  reduces both GO and metal ions. The RGO acts as a support  to stabilize metal nanoparticles.

The resulting G-carbon composite exhibited competitive catalytic activity  and superior methanol tolerance compared to a commercial Pt/C catalyst. Furthermore, it demonstrated significantly higher catalytic efficiency than a Pt/C catalyst.

The wavelength in a longitudinal wave is the distance between consecutive compressions or rarefactions. Compressions are analogs to peaks, and rarefactions to troughs of transverse waves, while amplitude refers to the particle displacement from equilibrium.

In a longitudinal wave, the wavelength is the distance from one compression to the next compression or from one rarefaction to the next rarefaction.

Most longitudinal waves consist of areas of higher pressure, known as compressions, where the particles in the medium are closest together, and areas of lower pressure, called rarefactions, where the particles are furthest apart. Therefore, the wavelength of a longitudinal wave can be defined as the distance between two consecutive compressions or two consecutive rarefactions.

The compression in a longitudinal wave is analogous to the peak of a transverse wave, while the rarefaction is analogous to the trough. The amplitude in longitudinal waves represents the extent of displacement of the medium's particles from their equilibrium position, occurring at both compressions and rarefactions.

The answer to your question is,

Metalloids. They are a mix of elements that are both metals and non-metals in one.

-Mabel <3

Answer:

Answer is A. Nucleus.

Flower is the reproductive organ of a flowering plant that contains male reproductive organ ( stamen) and female reproductive organ (carpel). Anther of the stamen produces male gamete and within the ovary of the carpel produced female gamete. After fertilization male gamete and female gamete fuses to form zygote.  Zygote is a single cell whose nucleus has chromosomes, where all the genetic information regarding development of fruit and seed are stored.    

Explanation:

As speed increases, the potential energy in the object decreases, while the kinetic energy increases. Both of those are forms of mechanical energy. Hope this helps!