why did early astronomers believe in the geocentric model?

Answer:

No they are not

Explanation:

Energy levels of electrons have fixed distance from the nucleus of an atom where electrons may be found.

orbitals is the path that electrons revolve

Answer:

Required Volume is 22.47ml

Explanation:

To make 2.0L of 0.2M sulfuric acid required moles = 0.2 x 2 = 0.4 moles

To get 0.4 from 17.8M required quantity = 1000/17.8 x 0.4 = 22.47ml

Answer:

i would say (c)

Explanation:

Answer:c

Explanation:

Answer:

601mmHg.

Explanation:

Step 1:

Data obtained from the question.

Initial pressure (P1) = 760mmHg

Initial temperature (T1) = 100°C = 100°C + 273 = 373K

Final temperature (T2) = 22°C = 22°C + 273 = 295K

Final pressure (P2) =..?

Step 2:

Determination of the new pressure at which the water will boil.

The new pressure on the at which the water will boil can be obtained as follow:

P1/T1 = P2/T2

760/373 = P2/295

Cross multiply to express in linear form

373 x P2 = 760 x 295

Divide both side by 373

P2 = (760 x 295) / 373

P2 = 601mmHg

Therefore, the new pressure at which the water will boil is approximately 601mmHg.

Answer:

C. 18-20 mm

Explanation:

Answer:

Sound waves and light waves need to change places

Explanation:

Just did this assignment on edge. Sound waves are mechanical because they need matter to travel through, while light waves are electromagnetic.

Answer:

Sound waves and light waves need to change places

Explanation:

Answer:

factory emissions

Explanation:

Answer:

62,790J

Explanation:

Q=mcT

= 250g*4.186J/gc*80-20

=250*4.186*60=62,790J

Answer:

[tex]N_{solute}=6.64x10^{-3}mol[/tex]

Explanation:

Hello,

In this case, we define molarity as shown below:

[tex]M=\frac{N_{solute}}{V_{solution}}[/tex]

Whereas we have the moles of the solute and the volume of the solution in litres, in such a way, for finding the moles we solve for it as shown below:

[tex]N_{solute}=M*V_{solution}[/tex]

[tex]N_{solute}=0.415\frac{mol}{L} *16.0mL*\frac{1L}{1000mL}\\ \\N_{solute}=6.64x10^{-3}mol[/tex]

Best regards.

Answer:

0.00664 moles of solute are needed to prepare the solution.

Explanation:

Molarity is a unit of concentration based on the volume of a solution and is defined as the number of moles of solute per liter of solution. In other words, molarity is defined as the number of moles of solute that are dissolved in a given volume and is determined by the following expression:

[tex]Molarity (M)=\frac{number of moles of solute}{volume}[/tex]

Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].

In this case:

Replacing:

[tex]0.415 M=\frac{number of moles of solute}{0.016 L}[/tex]

Solving:

number of moles of solute= 0.00664

0.00664 moles of solute are needed to prepare the solution.

Answer:

[tex]NaSO_{4}[/tex]

Explanation:

Asúmase que existen 100 gramos de compuesto, las cantidades molares de cada componente son, respectivamente: (Let assume that exist 100 grams of the composite, the molar quantities of each component are, respectively:)

Na

[tex]n = \frac{19.3\,g}{22.99\,\frac{g}{mole} }[/tex]

[tex]n = 0.839\,moles[/tex]

S

[tex]n = \frac{26.9\,g}{32.065\,\frac{g}{mole} }[/tex]

[tex]n = 0.839\,moles[/tex]

O

[tex]n = \frac{53.8\,g}{15.999\,\frac{g}{mole} }[/tex]

[tex]n = 3.363\,moles[/tex]

La fórmula molecular empírica es (The empirical molecular formula is):

[tex](Na_{0.839}S_{0.839}O_{3.363})_{1.192}[/tex]

[tex]NaSO_{4}[/tex]

Answer:

Volume will the gas occupy at [tex]70[/tex] kPa [tex]= 5.71[/tex]

Explanation:

As per the gas law

[tex]P_1V_1 = P_2V_2[/tex]

Here

[tex]P_1 =[/tex] initial pressure of the gas

[tex]P_2[/tex] = final pressure of the gas

[tex]V_1 =[/tex] Initial volume of the gas

[tex]V_2[/tex] =  the final volume of the gas

here,

[tex]P_1 = 80[/tex] kPa

[tex]V_1 = 5[/tex] mL

[tex]P_2 = 70[/tex]

Substituting the given values in above equation, we get -

[tex]80 * 5 = 70 * V_2\\V_2 = 5.71[/tex]

Volume will the gas occupy at [tex]70[/tex] kPa [tex]= 5.71[/tex]

Answer:

Option a. = 0.01 M

Explanation:

To do this, we need to gather the data:

E = 2.21 V

[Cl⁻] = 0.1 M

And the Redox reaction taking place is the following:

Zn(s) + Cl₂(g) <-------> Zn²⁺(aq) + 2Cl⁻(aq)       Q = [Zn] [Cl]²

E° Cl⁻/Cl₂ = 1.36 V

E° Zn/Zn²⁺ = -0.76 V

According to this, the expression to use will be the Nernst equation, and we can assume we are working at 25 °C, therefore, the Nernst equation will be:

E = E° - (0.059/n) logQ

E = E° - (0.059/n) ln([Cl⁻]² * [Zn²⁺])   (1)

From there, we can solve for Zn later.

First, we need to write the semi equation of oxidation and reduction, and get the standard potential of the cell:

Zn(s) --------> Zn²⁺(aq) + 2e⁻       E₁° = 0.76 V

Cl₂(g) + 2e⁻ -----------> 2Cl⁻(aq)   E₂° = 1.36 V

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

Zn(s) + Cl₂(g) -------> Zn²⁺(aq) + 2Cl⁻(aq)    E° = 0.76 + 1.36 = 2.12 V

Now, let's replace in (1) and then, solve for [Zn]:

2.21 = 2.12 - (0.059/2) log ([0.1]² * [Zn])

2.21 - 2.12 = -0.0295 log (0.01[Zn])

- 0.09 / 0.0295 = log (0.01[Zn])

-3.0508 = log (0.01[Zn])

10^(-3.0508) = 0.01[Zn]

8.8961x10⁻⁴ = 0.01[Zn]

[Zn²⁺] = 0.08896 M

This value can be rounded to 0.1 M. so the correct option will be option A.

Answer:

F, N O, C, B

Explanation:

Ionization on the periodic table, goes from left to right, so in order to decrease in ionization, you go right to left.

Therefore leading to (F)luorine, (N)itrogen, (O)oxygen, (C)arbon, and (B)oron

Answer:

Turbines.

Explanation:

Hello,

In this case, we define steam as high-energy vapor water, which has the capacity to be cooled to release energy to a system. For instance, turbines, use overheated steam to produce energy, by feeding the steam to the turbine's rotor blades in order to make the rotate and generate work. As a consequence of the rotation, the steam loses energy, for which it goes out from the turbine at low both temperature a pressure, even do, in some cases it could go out liquid so a condensation may occur.

Regards.

Answer:

Steam turbines

Explanation:

Mechanical advantage is used to describe the attainment of an amplified force output from a minimal force input

Steam is the water in gaseous form

Therefore, an example of where people use steam for mechanical advantage includes the steam turbines in power generation being turned by steam produced from burning water from a supply.

Here the expansion of the water to steam provides power to drive the the turbines so as to perform mechanical work.

Answer:

Producer

Primary Consumer

Secondary Consumer

Tertiary Consumer

Decomposer

Answer:

Full moon.

Explanation:

This diagram shows a full moon because the sunlight is shining directly onto the side of the moon facing the earth in this instance.

Answer:

It is A

Explanation:

Answer: 305 g of [tex]Be_3(PO_4)_2[/tex] will be produced from 38 grams  of beryllium oxide

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of} BeO=\frac{38g}{25g/mol}=1.52moles[/tex]

[tex]3BeO+2FePO_4\rightarrow Be_3(PO_4)_2+Fe_2O_3[/tex]

According to stoichiometry :

3 moles of [tex]BeO[/tex] produce = 1 mole of [tex]Be_3(PO_4)_2[/tex]

Thus 1.52 moles of [tex]BeO[/tex] will produce =[tex]\frac{1}{3}\times 1.52=0.507moles[/tex]  of [tex]Be_3(PO_4)_2[/tex]

Mass of [tex]Be_3(PO_4)_2=moles\times {\text {Molar mass}}=0.507moles\times 602g/mol=305g[/tex]

Thus 305 g of [tex]Be_3(PO_4)_2[/tex] will be produced from 38 grams  of beryllium oxide

Answer:

Type of reactions :

Answer:

evaporation

Explanation:

Answer:

Boiling

Explanation:

When a substance transitions from liquid to gas, it's called evaporation if it's on the surface, and boiling if it's all throughout the liquid.

Picture boiling water in a pot: it starts on the bottom, and the bubbles go toward the top. Evaporation starts on the surface.

Answer: Yes, the student is right, one should use pellets of the reactant should be heated and stirred for mixing properly.

Explanation:

In case of smaller particles the surface area that is being exposed increases and the due to this the reaction occurs faster.

Increasing the temperature of the temperature, increases the kinetic energy of the particles which helps in easy mixing of the particles.

The collision in between the particles also increase while stirring and thus the rate of reaction increases.

So, the heating and stirring is more preferred over powered reactant for making a solution quickly.

Answer:

water and carbon dioxide

Explanation:

Chemical weathering is the process of changing the composition of a mineral in order to break it down. The two agents that are the biggest proponents of chemical weathering are water and carbon dioxide. Water is used in a process called Hydrolysis which uses it to break down substances such feldspar in granite rocks changing to clay. While Carbon Dioxide in the atmosphere dissolves in rainwater forming carbonic acid, which slowly dissolve rocks when it comes into contact with them.

Answer:

Phosphorus

Explanation:

Group 5A has 5 valence electrons.

3 electron shells equals 15 electrons on Phosphorus. Furthermore, 2 on shell 1, 8 on shell 2, and 5 on shell 3.

- Hope that helps! Please let me know if you need further explanation.

Answer:

% yield = 44.5 %

Explanation:

Step 1: Data given

Mass of Mg3N2 = 100.0 grams

Mass of H2O = 75.0 grams

Mass of NH3 = 15.0 grams

Molar mass of Mg3N2 = 100.95 g/mol

Molar mass of H2O = 18.02 g/mol

Molar mass of NH3 = 17.03 g/mol

Step 2: The balanced equation

Mg3N2 + 3H2O → 3MgO + 2NH3

Step 3: Calculate moles

Moles = mass / molar mass

Moles Mg3N2 = 100 grams / 100.95 g/mol

Moles Mg3N2 = 0.99 moles

Moles H2O = 75.0 grams / 18.02 g/mol

Moles H2O = 4.16 moles

Moles NH3 = 15.0 grams / 17.03 g/mol

Moles NH3 = 0.88 moles

Step 4: Calculate the limiting reactant

For 1 mol Mg3N2 we need 3 moles H2O to produce 3 moles MgO and 2 moles NH3

Mg3N2 is the limiting reactant. It will completely be consumed (0.99 moles)

H2O is in excess. There will react 3*0.99 = 2.97 moles

There will be produced 2*0.99 = 1.98 moles of NH3

Step 5: calculate mass of NH3

Mass of NH3 = moles NH3 * molar mass NH3

Mass NH3 = 1.98 moles * 17.03 g/mol

Mass of NH3 = 33.7 grams

Step 6: Calculate the % yield

%yield = (actual yield/ theoretical yield) * 100 %

% yield = (15.0 grams / 33.7) * 100 %

% yield = 44.5 %

The percentage yield of ammonia in the given reaction has been 44.44%.

The balanced chemical reaction can be:

[tex]\rm Mg_3N_2\;+\;3\;H_2O\;\rightarrow\;3\;MgO\;+\;2\;NH_3[/tex]

The moles can be given as:

Moles = [tex]\rm \dfrac{weight}{molecular\;weight}[/tex]

Moles of [tex]\rm Mg_3N_2[/tex] = 0.99 mol

Moles of [tex]\rm H_2O[/tex] = 4.16 mol

Moles of [tex]\rm NH_3[/tex] = 0.88 mol

The limiting reactant can be:

From the balanced equation for 3 moles of water, there has been 1 mole of magnesium nitrite. So, for 4.16 moles of water, there will be 1.38 moles of [tex]\rm Mg_3N_2[/tex]. Since the amount of [tex]\rm Mg_3N_2[/tex] has been completely consumed in the reaction, [tex]\rm Mg_3N_2[/tex] has been the limiting reactant.

So, the moles of ammonia produced =

1 moles [tex]\rm Mg_3N_2[/tex] = 2 moles ammonia.

0.99 moles [tex]\rm Mg_3N_2[/tex] = 0.99 [tex]\times[/tex] 2 moles [tex]\rm NH_3[/tex]

0.99 moles [tex]\rm Mg_3N_2[/tex] = 1.98 moles of ammonia.

The theoretical yield of ammonia = 1.98 moles

The actual yield of ammonia = 0.88 mol.

% Yield of Ammonia = [tex]\rm \dfrac{Actual\;yield}{Theoretical\;yield}\;\times\;100[/tex]

% Yield of Ammonia = [tex]\rm \dfrac{0.88}{1.98}\;\times\;100[/tex]

% Yield of Ammonia = 44.44 %

For more information about percentage yield, refer to the link:

https://brainly.com/question/12809634

1107 Joule is the amount of energy which is needed to change 88.0 g of solid benzene at 5.53°C into liquid benzene, also at 5.53°C.

In order to perform work and to produce heat and light, energy must be delivered to a body or to an external physical system. Energy is a quantitative property. Energy is a preserved resource; according to the rule of conservation of energy, energy can only be transformed from one form to another and cannot be created or destroyed. 

A moving object's kinetic energy, an object's potential energy, an object's elastic energy, chemical energy linked to chemical reactions, electromagnetic radiation's radiant energy, and the internal energy of a thermodynamic system are examples of common kinds of energy.

mole of benzene = 85.2/78.11 =1.09mol

1 mole of benzene requires  10.19 kJ/mol energy

1.09 mole of benzene requires 1.09× 10.19 kJ/mol = 11.107kJ/mol energy

                                                                                  = 1107 Joule energy

Therefore,  1107 Joule is the amount of energy which is needed to change 88.0 g of solid benzene at 5.53°C into liquid benzene, also at 5.53°C.

To learn more about energy, here:

https://brainly.com/question/29763772

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How compact a certain object or person is

Answer:

Density is a measure of mass per unit of volume.The average density of an object equal its total mass divided by its total volume.

Answer: Radioactive waste

Explanation:

The nuclear fission reaction consists of heavy atomic particles or heavy nucleus, like plutonium and uranium and in radioactive heavy metals. In the fission reaction the nucleus get split into equal masses of particles. This process is associated with release of large amount of energy. The fission of radioactive waste can cause deadly mutations in living beings.      

Answer:

[tex]3 Mg(s) + N_2(g) = Mg_3N_2(s)[/tex]

Explanation:

The valance of magnesium atom is  [tex]+2[/tex]

While the valence of nitrogen atom is [tex]- 3[/tex]

Let us first write the first  half-reactions

[tex]Mg ---> Mg^{2+} + 2e^{-}[/tex]

The second half reaction is

[tex]2N + 6e^- -----> N_2[/tex]

Adding the above two reactions and writing the final reaction, we get -

[tex]Mg + N2 = Mg_3N_2[/tex]

The balance equation is

[tex]3 Mg(s) + N_2(g) = Mg_3N_2(s)[/tex]

Answer:

B. 47.3

Explanation: