List the metals Mg, Cu, Au, Na and Al in the decreasing order of their reactivity with air.

Answer:

1.Chemistry is the scientific discipline involved with elements and compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.

2.The scientific method is an empirical method of acquiring knowledge that has characterized the development of science since at least the 17th century. It involves careful observation, applying rigorous skepticism about what is observed, given that cognitive assumptions can distort how one interprets the observations.

Answer:

Explanation:

[tex]Move \: the\:decimal \:point\:,\\3 \:times\:to\:the \:right = 24\\\\When \:the\:decimal\:point \: moves\\\:to\:the \:right\:it\:becomes\:a \:negative\:power\\\\0.024= 24 \times 10^-^3[/tex]

Answer:

No

Explanation:

Droplets or aerosols. When an infected person coughs, sneezes, or talks, droplets or tiny particles called aerosols carry the virus into the air from their nose or mouth. Anyone who is within 6 feet of that person can breathe it into their lungs.

Airborne transmission. Research shows that the virus can live in the air for up to 3 hours. It can get into your lungs if someone who has it breathes out and you breathe that air in.

Surface transmission. Another way to catch the new coronavirus is when you touch surfaces that someone who has the virus has coughed or sneezed on. You may touch a countertop or doorknob that's contaminated and then touch your nose, mouth, or eyes. The virus can live on surfaces like plastic and stainless steel for 2 to 3 days. To stop it, clean and disinfect all counters, knobs, and other surfaces you and your family touch several times a day.

Fecal-oral. Studies also suggest that virus particles can be found in infected people's poop. But experts aren't sure whether the infection can spread through contact with an infected person's stool. If that person uses the bathroom and doesn't wash their hands, they could infect things and people that they touch.

[tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex] is the correct electron configuration for an element with five electrons in the third energy level.

Elements are the simplest substances which cannot be broken down using chemical methods.

The shell nearest to the nucleus, 1n, can carry two electrons, while the next shell, 2n, can carry eight, and the third shell, 3n, can carry up to eighteen.

The third shell carries 18 electrons; 2 in a 3s orbital; 6 in three 3p orbitals; and 10 in five 3d orbitals. The fourth shell carries  32 electrons; 2 in a 4s orbital; 6 in three 4p orbitals; 10 in five 4d orbitals; and 14 in seven 4f orbitals.

The element would be phosphorus. Its electron configuration is [tex]1s^2 2s^2 2p^6 3s^2 3p^3[/tex]

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Answer:

See explanation

Explanation:

The wittig reaction is an organic reaction in which an aldehyde or a ketone reacts with a phosphonium ylide to give an alkene. This phoshonium ylide that participates in the reaction is usually generated insitu in the system by reaction of an alky or aryl triphenylphosphonium halide salt with a base(sodium hydroxide is mostly used).

In this particular reaction 4-methylbenzaldehyde and benzyltriphenylphosphonium chloride were reacted together in the presence of sodium hydroxide and the product with the structure shown in the answer was obtained as the major isomer produced in the reaction.

Answer: answer is C

Explanation:

Its product is heavier than each of its reactants is true about this ₇N¹⁴ + ₁H¹ →  ₈O¹⁵ reaction

A nuclear reaction is a reaction in which one or more than one nuclides are generate and it collides between two atomic nuclei or one atomic nucleus.

The reaction is  

₇N¹⁴ + ₁H¹ →  ₈O¹⁵

Now equating the mass number of both sides

14 + 1 = 15 + a

a = 0

Equating atomic number of both sides

7 + 1 = 8 + x

x = 0

Thus, we can say that its product is heavier than each of its reactants is true about this reaction

Hence, option C is correct answer.

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Answer:

The solution formed is called Barium hydroxide Ba(OH)2 and metal A is Barium

Explanation:

All basic oxides except BaO are insoluble in water

Answer:

conclusion

Explanation:

it can't be a hypothesis since tests are carried out to verify so it is not a theory

an introduction to an experiment only gives the basis of what we are investigating therefore nothing has been proven and the question is still unanswered

The overall takeaway of an experiment’s results is the conclusion. Hence, option C is correct.

A hypothesis is a testable statement about the relationship between two or more variables or a proposed explanation for some observed experiment.

The overall takeaway of an experiment’s results can't be a hypothesis since tests are carried out to verify so it is not a theory

An experiment only gives an idea about the investigation therefore nothing has been proven and the question is still unanswered.

Hence, the overall takeaway of an experiment’s results is the conclusion.

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Answer:

CNa203

Explanation:

thats is method in the picture send

Answer:

The  pressure is [tex]P_f = 0.93 \ atm[/tex]

Explanation:

From the question we are told that

   The  volume of  Ne  is  [tex]V_N = 2.50 \ L[/tex]

    The volume  of  CO is  [tex]V_C = 2.00 \ L[/tex]

    The  pressure of  [tex]Ne[/tex] is  [tex]P_N = 1.09 \ atm[/tex]

      The  pressure of  CO is [tex]P_C = 0.773 \ atm[/tex]

The  number of  moles of  Ne present is evaluated using the ideal gas equation as

      [tex]n_N = \frac{P_N * V_N}{R T}[/tex]

=>   [tex]n_N = \frac{1.09 * 2.50 }{R T} = \frac{2.725}{RT}[/tex]

The  number of  moles of  CO present is evaluated using the ideal gas equation as

      [tex]n_N = \frac{P_C * V_C}{R T}[/tex]

=>   [tex]n_N = \frac{0.73 * 2.00 }{R T} = \frac{1.46}{RT}[/tex]

The  total number of moles of gas present is evaluated as

        [tex]n_T = n_N + n_C[/tex]

        [tex]n_T = \frac{2.725}{RT} + \frac{1.46}{RT}[/tex]

      [tex]n_T = \frac{4.185}{RT}[/tex]

The  total volume of gas present when valve is opened is  mathematically represented as

                [tex]V_T = V_N + V_C[/tex]

    =>        [tex]V_T = 2.50 + 2.00 = 4.50 \ L[/tex]

So

  From the ideal gas equation the final pressure inside the system  is mathematically represented as

         [tex]P_f = \frac{n_T * RT }{ V_T}[/tex]

=>      [tex]P_f = \frac{[\frac{4.185}{RT} ] * RT }{ 4.50}[/tex]

=>       [tex]P_f = 0.93 \ atm[/tex]

Answer:

materials which do not show the quality of lustre i.e. shiney surface

for eg- non metals except Iodine

Explanation:

hope it helps u plz mark as the brainliest

Answer:

These are materials that don't have lustre

Explanation:

They are not shiny.

They include non-metals but not iodine.

Hope it helps.

Answer:

+2

Explanation:

Oxidation number of an element, also called its oxidation state, is the number of electrons its atoms lost or gain in the process of forming a chemical compound.

To determine the oxidation state of an element or compound;

- The sum of all the oxidation numbers in a neutral compound must equal zero (0).

In the compound: Fe2(CO3)2

This compound is a neutral one, hence, its oxidation state is equal to zero (0).

It contains a polyatomic ion (carbonate ion) i.e. CO3 2-, whose net charge is -2.

Hence, to find the oxidation number of Iron (Fe), which is represented by X, in the compound, we say;

X(2) + -2(2) = 0

2X + -4 = 0

2X - 4 = 0

2X = 4

X = +2

Therefore, the oxidation number of Fe in Fe2(CO3)2 is (+2)

The compound Fe2(CO3)2 is called Iron (II) carbonate

Oxidation number of Fe in [tex]\rm Fe_2(CO_3)_2[/tex] is 2. An atom's oxidation number is a positive or negative number.

A notion used in chemistry to characterise the relative electron distribution and the level of oxidation or reduction of atoms in a compound or ion is known as the "oxidation number," sometimes known as the "oxidation state." Based on the presumption that electrons in chemical bonds are entirely transmitted to the more electronegative atom, it is a method of bookkeeping that assigns a notional charge to each individual atom in a molecule or ion.

The -4 stands for the overall charge that the carbonate ions provided, and the x is the Fe's oxidation number.

2x + (-4) = 0

2x - 4 = 0

2x = 4

x = 4/2

x = 2

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Answer:

Scientists

Explanation:

Scientists because they are the one who makes hypothesis.

Answer:

The system will shift to the left producing more moles of gases trying to maintain the original pressure of the system

Explanation:

Based on LeChatelier's principle, a change in temperature, pressure, volume or concentration on a system result in an opposing change trying to maintain the initial equilibrium conditions.

In the reaction:

N₂(g) + 3H₂(g) ⇄ 2NH₃(g)

4 moles of gas reacts producing 2 moles of gas.

In a gas reaction, the system will try to maintain the total pressure.

If the volume of the container increases, the system will shift to the side of the reaction that has more moles of gases in order to maintain the pressure.

That means if in the reaction the volume of the container increase from 2.0L to 4.0L the system will shift to the left producing more moles of gases trying to maintain the original pressure of the system.

Answer:

The answer is "Option D".

Explanation:

The entire ionic equation for all the substances, which are ionic compounds but are available in an aquatic is represented in the form with ions in the full ionic equation.  

In the Net ionic equation, it doesn't have the particulate matter throughout the net ionic equations throughout the equations.  

In the Spectator ions, it doesn't participate in interactions mostly on reaction and the material hand. From both sides, the very same ions are present.  

The evenly balanced chemical formula is,

[tex]2KOH (aq)+ H_2SO_4(aq) \longrightarrow 2H_2O(l) + K_2SO_4[/tex]

It is the separate organic compound that full ion formula will match the choice D.

Answer:

a) The similarities in their structure are;

1) The two isotopes have the same number of protons in their nucleus

2) The two isotopes have the same number of electrons in their orbit

3)The basic chemical properties of the two isotopes are the same

b) The differences in their structure are;

1) The number of neutrons in their nucleus are different

6 for carbon 12 and 8 for carbon 14

2) The structure of carbon 12 is stable while the structure of carbon 14 disintegrates

3) The isotopes have different densities, therefore, different packing

Explanation:

The atomic number is the number of protons in the nucleus of an atom

The mass number is the sum or total number of protons and neutrons in an atom

Given that the atomic number of all carbon atoms = 6

The number of protons in all carbon atoms = 6

Given that some of the carbon atoms have a mass number of 12 while others have a mass number 14, we have

Therefore, the number of neutrons in some of the carbon atoms = 12 - 6 = 6

The number of neutrons  in the remaining of carbon atoms = 14 - 6 =  8

Therefore the carbon atom has two isotopes including ¹²₆C and ¹⁴₆C.

Answer:

The mass of NH₃ left over = 0.91 g of NH₃

The mass of H₂ left over = 8.2 g of H₂

Explanation:

The given information are;

The mass of the carbon monoxide present in the reaction = 25.0 g

The mass of the ammonia present in the reaction = 8.50 g

The mass of the hydrogen present in the reaction = 10.0 g

The above masses reacts to produce water and acetonitrile (CH₃CN)

The balanced chemical equation for the reaction is given as follows;

2CO + NH₃ + 2H₂ → CH₃CN + 2H₂O

Therefore, two moles of CO reacts with one mole of NH₃ and  two moles of H₂ to produce one mole of CH₃CN and two moles of H₂O

The molar mass of CO = 28.01 g/mol

The molar mass of NH₃ = 17.031 g/mol

The molar mass of H₂ = 2.0159 g/mol

The molar mass of H₂O = 18.015 g/mol

The molar mass of CH₃CN = 41.05 g/mol

The number of moles of CO present = 25/28.01 = 0.893 moles

The number of moles of NH₃ present = 8.5/17.031 = 0.5 moles

The number of moles of H₂ present = 10/2.0159 = 4.96 moles

Therefore, 0.893 moles of CO reacts with 0.893/2 mole of NH₃ and  0.893 moles of H₂ to produce 0.893/2 mole of CH₃CN and 0.893 moles of H₂O

The excess reactants left are;

0.5 - 0.893/2 = 0.0535 moles of NH₃ with mass 0.0535 × 17.031 = 0.91 g

4.96 - 0.893 = 4.067 moles of H₂ with mass 4.067 × 2.0159 = 8.2 g

The mass of NH₃ left over = 0.91 g of NH₃

The mass of H₂ left over = 8.2 g of H₂.

Answer:

a) 1.392 x 10^6 g/cm^3

b) 8.69 x 10^7 lb/ft^3

Explanation:

mass of the star m =  2.0 x 10^36 kg

radius of the star (assumed to be spherical) r = 7.0 x 10^5 km = 7.0 x 10^8 m

The density of substance ρ = mass/volume

The volume of the star = volume of a sphere = [tex]\frac{4}{3}\pi r^{3}[/tex]

==> V = [tex]\frac{4}{3}*3.142*(7.0*10^8)^{3}[/tex] = 1.437 x 10^27 m^3

density of the star ρ = (2.0 x 10^36)/(1.437 x 10^27) = 1.392 x 10^9 kg/m^3

in g/cm^3 = (1.392 x 10^9)/1000 = 1.392 x 10^6 g/cm^3

in lb/ft^3 =  (1.392 x 10^9)/16.018 = 8.69 x 10^7 lb/ft^3

Answer:

Rubbing your hands together converts mechanical energy to thermal energy. Turning on a light switch converts mechanical energy to electrical and radiant energy.

Answer:

Fórmula empírica: C₂H₂N

Fórmula molecular: C₄H₄N₂

Explanation:

Un compuesto que contiene carbono hidrógeno y nitrógeno con fórmula CₐHₓNₙ es sometido a combustion produciendo:

CₐHₓNₙ + O₂ → aCO₂ + x/2 H₂O + nNO₂

Con la masa de dióxido de carbono y agua podemos encontrar las moles de carbono e hidrógeno y su aporte a los 0.452g de muestra que fueron puestos en combustión, así:

Moles C:

Moles C = Moles CO₂ = 0.994g CO₂ ₓ (1mol / 44g) = 0.0226 moles C

Masa C: 0.0226 moles C ₓ (12.01g / mol) = 0.271g Carbono hay en la muestra

Moles H:

Moles H = 2 Moles H₂O = 0.203g H₂O ₓ (1mol / 18g) = 0.0113 moles H₂O = 0.0226 moles H

Masa H: 0.0226 moles H ₓ (1.01g / mol) = 0.023g Hidrógeno hay en la muestra

Así, la masa de nitrógeno en la muestra y sus moles son:

Masa N = 0.452g - 0.271g C - 0.023g H

Masa N = 0.158g Nitrógeno

Y su moles son:

0.158g ₓ (1 mol / 14.01g) = 0.0113 moles N

Con las moles de C, H y N podemos determinar la formula empírica que se define como: "La relación de números enteros más simple entre la cantidad de átomos presentes en una mólecula. Si usamos como base las moles de nitrógeno (Valor menor):

Relación H/N: 0.0226 mol / 0.0113 mol = 2

Relación C/N: 0.0226 mol / 0.0113 mol = 2

Relación N/N: 0.0113 mol / 0.0113 mol = 1

Así, la fórmula empírica es:

Esta fórmula empírica tiene una masa molar de:

2C = 2*12 g/mol = 24g/mol

2H = 2*1g/mol = 2g/mol

N = 14g/mol

24+14+2 = 40g/mol

Como la masa molecular del compuesto es 80g/mol (Dos veces la de la fórmula empírica, la fórmula molecular es 2 veces la fórmula empírica:

Answer:

A few of the positive particles aimed at a gold foil seemed to bounce back.

Explanation:

Rutherford's experiment took the search for the structure of the atom a step further. In this experiment, a narrow beam of alpha particles emitted from a source was used to bombard a thin gold foil.

The scattering of the alpha particles was detected by a movable ZnS screen. It was found that most of the alpha particles followed a straight path through the gold foil but some were scattered through large angles and some even scattered backwards.

Following this experiment, Rutherford decided on his planetary model of the atom in which the nucleus is at the core of the atom with electrons moving round the nucleus in orbits. Rutherford was awarded a Nobel prize for this work.

Answer:

a

Explanation:

edge 2020

Answer:

Heat of sublimation of Li(s) = 160.5 kJ/mol

Explanation:

Given that:

[tex]\mathtt{2Li(s) + \dfrac{1}{2} I_2(g) \to 2LiI(s)}[/tex]

ΔH = –292 kJ

The heat of formation for the above reaction =  –292 kJ × 2 =  -584 kJ/mol

[tex]\mathtt{Li^+_{(g)} + I^-_{(g)} \to LiI_{(s)}}[/tex]

The lattice energy of LiI(s) = -753 kJ/mol

[tex]\mathtt{Li(g)\to Li^+(g) + e^- }[/tex]

The ionization energy of LiI(s) = +520 kJ/mol

[tex]\mathtt{I_2_{(g)} \to 2I_{(g)} }[/tex]

The Bond Energy of I₂(g) = 151 kJ/mol

[tex]\mathtt{I_{(g)} + e^- \to I^-_{(g)}}[/tex]

The electron affinity of I(g) = -295 kJ/mol

Heat of sublimation: Sublimation is the process of changing of a solid matter into gas without passing through the liquid stage, Now, the molar heat of sublimation is the amount of energy that must be added to a mole of solid  to turn it directly into a gas without any interference through the liquid phase provided the pressure is  constant.

From  the above reactions: The heat of sublimation  of Li(s) can be calculated by the sum total of the following.

[tex]\mathtt{Li_{(s)} + \dfrac{1}{2} I_2_{(g)} \to LiI_{(s)} \ \ -292 kJ/mol} \\ \\\mathtt{I_{(g)} \to \dfrac{1}{2} I2(g) \ \ -75.5 kJ/mol} \\ \\ \mathtt{I^-(g) \to I(g) + e^- \ \ +295 kJ/mol} \\ \\ \mathtt{LiI(s) \to Li^+_{(g)} + I^-_{(g)} \ \ +753 kJ/mol} \\ \\ \mathtt{Li^+_{(g)} + e^- \to Li(s) \ \ -520 kJ/mol} \\ \\[/tex]

[tex]\mathtt{Li(s) \to Li(g)}[/tex] = (-292 +(-75.5)+295+753+(-520)) kJ/mol

[tex]\mathtt{Li(s) \to Li(g)}[/tex] =  160.5 kJ/mol

Heat of sublimation of Li(s) = 160.5 kJ/mol

Answer:

The atomic number of the atom is 14.

Explanation:

The following data were obtained from the question:

Valence electrons = 4

Atomic number =.?

From the question given, we were told that the valence electron is in the m shell. Thus, we can say:

M shell = 4 electrons

The number of shells of the atom can be written in the order K, L, M with M as the last shell because we were told that the valence electrons i.e electrons in the outer shell is located at the M shell.

From a detailed knowledge of atom,

K shell = 1st shell

L shell = 2nd shell

M shell = 3rd shell

The first shell, K of an atom can only accommodate 2 electrons while others can accommodate a maximum of 8 electrons.

Note: we can only put electrons in another shell if a shell is already having 8 electrons. This rule only applies to the 2nd shell and above.

Thus, the atom in question has the following electrons:

K shell = 1st shell = 2 electrons

L shell = 2nd shell = 8 electrons

M shell = 3rd shell = 4 electrons

To get the atomic number of the atoms, we simply add all the electrons together.

This is illustrated below:

Atomic number = 2 + 8 + 4

Atomic number = 14

Therefore, the atomic number of the atom is 14.

Answer:

The answer on Edge is,

C. the number of valence electrons an atom has

Answer:

[tex]4.85 * 10^4\ mL[/tex]

Explanation:

Given

485 L

Required

Determine the measurement not equal to 485L

[tex]0.485\ kL[/tex]

From standard unit of conversion;

1 KL = 1000 L

Multiply both sides by 485

[tex]485 * 1 KL = 485 * 1000 L[/tex]

[tex]485KL = 485000L[/tex]

Divide both sides by 1000

[tex]\frac{485KL}{1000} = \frac{485000L}{1000}[/tex]

[tex]0.485KL = 485L[/tex]  ---- This is equivalent

---------------------------------------------------------------------------------------------

[tex]4.85 * 10^4\ mL[/tex]

From standard unit of conversion;

1000 mL = 1 L

Multiply both sides by 485

[tex]485 * 1000 mL = 1 L * 485[/tex]

[tex]485000\ mL = 485\ L[/tex]

Convert to standard form

[tex]4.85 * 10^5\ mL = 485\ L[/tex]

Hence; [tex]4.85 * 10^4\ mL[/tex] is not equivalent to 485L

---------------------------------------------------------------------------------------------

[tex]48500 \ cL[/tex]

From standard unit of conversion;

100 cL = 1 L

Multiply both sides by 485

[tex]485 * 100 cL = 1 L * 485[/tex]

[tex]48500\ cL = 485\ L[/tex]

Convert to standard form

[tex]4.85 * 10^4\ cL = 485\ L[/tex] ---- This is equivalent

---------------------------------------------------------------------------------------------

[tex]4.85 * 10^8 \[/tex] μL

From standard unit of conversion;

1000000 μL = 1 L

Multiply both sides by 485

[tex]485 * 1000000uL = 1 L * 485[/tex]

[tex]485000000uL = 485\ L[/tex]

Convert to standard form

[tex]4.85 * 10^8\ uL = 485\ L[/tex] ---- This is equivalent

From the list of given options;

[tex]4.85 * 10^4\ mL[/tex] is not equivalent to 485L

Respuesta:

21.8 L

Explicación:

Paso 1: Escribir la reacción balanceada

CaCO₃ ⇒ CaO + CO₂

Paso 2: Convertir 450 g de CaCO₃ a moles

La masa molar de CaCO₃ es 100.09 g.

450 g × (1 mol/100.09 g) = 4.50 mol

Paso 3: Calcular los moles de CO₂ que se forman a partir de 4.50 moles de CaCO₃

La relación molar de CaCO₃ a CO₂ es 1:1. Los moles de CO₂ formados son 1/1 × 4.50 mol = 4.50 mol.

Paso 4: Convertir la temperatura a Kelvin

Usaremos la siguiente expresión.

K = °C + 273.15 = 200°C + 273.15 = 473 K

Paso 5: Calcular el volumen de CO₂

Usaremos la ecuación del gas ideal.

P × V = n × R × T

V = n × R × T / P

V = 4.50 mol × (0.082 atm.L/mol.K) × 473 K / 8 atm

V = 21.8 L

Answer:

≈ 0.104 liters  

Explanation:

We can use Boyle's Law: [tex]P_{1}V_{1} = P_{2}V_{2}[/tex]

P₁ = 2.50 atm

V₁ = 25.0 mL

P₂ = 457 mmHg

V₂ = ?

Because pressure should be in atm we will convert 457 mmHg to units in atm:

1 atm = 760mmHg so we can divide 457 by 760 and we get ≈ 0.601atm

Next we can plug in the units to the equation for Boyle's Law:

(2.50)(25.0) = (0.601)(V₂)

Solve for V₂

V₂ will give you ≈ 104mL or 0.104L

Either is correct depending on which unit they are asking you to use

Answer:

Explanation:

The glass (which does not crystallize even though it is accepted) of a window is NOT a mineral, since it is neither a substance of natural origin (although it is manufactured from natural components) nor does it have a defined crystalline structure, that is, the atoms they are not arranged in an orderly and regular way along axes and planes forming flat faces that keep a symmetry.

Remember that a mineral is defined as a solid, inorganic, homogeneous substance, of natural origin, with a crystalline structure and a determined and well-defined chemical composition within narrow margins and that has regular and characteristic physical properties.

Explanation: No, glass is not a mineral. ... Definable chemical composition: SiO2 *Actually, most industrially-produced glass is not pure silica, but having impurities is still a definable chemical composition so this part of the definition is ok. Orderly arrangement of atoms in a lattice: NO.