3. How can millions of
compounds be made from the
atoms of about 100 elements?

Answer Tu mama por si acaso

Explanation:

jkand

Answer:

See explanation

Explanation:

The solar system consists of the sun at the core surrounded by all the planets in their proper order. Similarly, the Bohr model of the atom upholds Rutherford's planetary model in which the atom was said to have a positive core surrounded by electrons moving in orbits just as the planets orbit round the sun.

The difference between the two models is that electrons are able to move from one energy level to another. This assumption violates the principles of the solar system because the position of the planets are fixed in their orbits.

The theoretical basis behind this assumption is that each spectral line is produced by the transition of electrons from one energy level to another.

Answer:

0.81 moles H2

Explanation:

The equation of the reaction is;

Mg(s) + 2HCl(aq) ------>MgCl2(aq) + H2(g)

Number of moles of HCl reacted = concentration * volume

Number of moles of HCl reacted = 6.44 * 250/1000

Number of moles of HCl reacted = 1.61 moles of HCl

If 2 moles of HCl produces 1 mole of H2

1.61 moles of HCl produces 1.61 * 1/2 = 0.81 moles H2

Answer: 157.3 g CO

Explanation:

Fe2O3  + 3CO —> 3CO2 + 2Fe [1 mol + 3 mol —> 3 mol + 2 mol]

3 mol CO —> 2 mol Fe

3*28g —> 2*56g

amt CO 3*28*209.7/(2*56) = 157.3g

Explanation:

How many neutrons are there in the nucleus of arsenic?42 neutrons

The nucleus consists of 33 protons (red) and 42 neutrons (blue).

Answer:

A nivel microscópico y en el marco de la Teoría cinética, es el total de la energía cinética media presente como el resultado de los movimientos aleatorios de átomos y moléculas o agitación térmica, que desaparecen en el acto.

Explanation:

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Answer:

Explanation:

Measurement made = 100.2 °C

uncertainty = 0.1°C

percent uncertainty = .1 x 100 / 100.2

= .099 %

2 nd thermometer :

Measurement made = 99.0 °C

uncertainty = 0.5°C

percent uncertainty = .5 x 100 / 99

= .505  %

Percent error :

1 st thermometer

Error = 100.2 - 100 = .2 °C

measurement = 100.2

percent error = .2 x 100 / 100.2

= .1996 %

2 nd thermometer

Error = 100.00 - 99 = 1.00 °C

measurement = 99

percent error = 1 x 100 / 99

= 1.01  %

Percent uncertainty is the measure of degree of error region with the  uncertainty in the measurement.

The percentage error is the difference in the measurement of the values with actual value.

The percent uncertainty (%U) is calculated by:

[tex]\% U=\rm \dfrac{Uncertainty}{Measurement}\;\times\;100[/tex]

The percent error (%E)  is calculated by:

[tex]\%E=\rm \dfrac{error\;value-actual\;value}{error\;value}\;\times\;100[/tex]

The Recorded temperature = 100.2 degree Celsius

The actual temperature = 100 degrees Celsius

The uncertainty in the readings is 0.1 degree Celsius

The percent uncertainty is given by:

[tex]\%U=\dfrac{0.1}{100.2}\;\times\;100\\\\ \%U=0.099\;\%[/tex]

The percent uncertainty of digital thermometer is 0.099 %.

The percent error is given by:

[tex]\% E=\dfrac{100.2-100}{100.2}\;\times\;100 \\\\\% E=\dfrac{0.2}{100.2}\;\times\;100\\\\ \% E=0.1996\;\%[/tex]

The percent error of digital thermometer is 0.1996 %.

The Recorded temperature = 99 degree Celsius

The actual temperature = 100 degrees Celsius

The uncertainty in the readings is 0.5 degree Celsius

The percent uncertainty is given by:

[tex]\%U=\dfrac{0.5}{99}\;\times\;100\\\\ \%U=0.505\;\%[/tex]

The percent uncertainty of analog thermometer is 0.505%.

The percent error is given by:

[tex]\% E=\dfrac{100-99}{99}\;\times\;100 \\\\\% E=\dfrac{1}{99}\;\times\;100\\\\ \% E=1.01\;\%[/tex]

The percent error of analog thermometer is 1.01 %.

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Answer:

question not clear can u rewrite

Answer:

3.769022740695677

Explanation:

Answer:We get 1.81×1024 water molecules... Explanation: We assess the molar quantity of water in the usual way... Number of moles=massmolar mass.

brainliest plz

Answer:

it is Glucose hope it helps

Answer:

Glucose and DNA

Explanation:

Complex macromolecules are the combination of more than two molecules which are large and complex. The major types of complex macromolecules consists of 4 types which are carbohydrates, lipids, proteins, and nucleic acids.

Glucose is one of the carbohydrates, while DNA is another form of nuclei acid.

Answer: 1and 4

Explanation: iron is an element not an alloy. An ionic lattice is not bonded covalently.

Answer:

26.67 mol HCl

Explanation:

Al(OH)₃ + 3HCl → AlCl₃ + 3H₂O

In order to solve this problem, we need to convert Al(OH)₃ moles to HCl moles.

To do so we use the stoichiometric ratios of the balanced reaction:

Thus 26.67 moles of HCl would react completely with 8.89 moles of Al(OH)₃.

Answer:

HC₂H₃O₂ + NaHCO₃ —> NaC₂H₃O₂ + CO₂ + H₂O

The coefficients are: 1, 1, 1, 1, 1

Explanation:

_HC₂H₃O₂ + _NaHCO₃ —> _NaC₂H₃O₂ + _CO₂ + _H₂O

To balance an equation, we simply do a head count of the individual elements and ensure they are balanced on both side.

For the above equation, we shall balance it as :

HC₂H₃O₂ + NaHCO₃ —> NaC₂H₃O₂ + CO₂ + H₂O

Reactant:

H = 5

C = 3

O = 5

Na = 1

Product:

H = 5

C = 3

O = 5

Na = 1

From the above, we can see that each element is the same on both side of the equation. Thus the equation is already balanced

HC₂H₃O₂ + NaHCO₃ —> NaC₂H₃O₂ + CO₂ + H₂O

The coefficients are: 1, 1, 1, 1, 1

Answer:

5280 feet per mile.  5280 feet divided 60 minutes then divide by 60 gives you the feet per second.  multiply by 5.... 7 and 1/3 feet in 5 seconds.

Answer:

16.09 kg

Explanation:

To solve this problem first we convert those 5.0 gallons of ethanol into liters:

Now we calculate the mass of that volume of ethanol, using its density:

We convert 18.9 L ⇒ 18.9 * 1000 = 18900 mL

Finally we convert the masses of the bottle and shipping container and packaging and add them to the mass of ethanol:

So the shipping weight would be 16088.04 g, or 16.09 kg

Answer:

13. t = 1183 min and 0.50 M.

14. [tex]t_{1/2}=2.67x10^{-8}hr[/tex]

Explanation:

Hello!

13. In this case, according to the units, we infer this is a second-order reaction which has the following integrated rate law:

[tex]\frac{1}{[A]} =\frac{1}{[A]_0} +kt[/tex]

Which can be solved for the time as shown below:

[tex]t=\frac{ \frac{1}{[A]}-\frac{1}{[A]_0}}{k}[/tex]

Thus, we plug in the given concentrations and rate constant to obtain:

[tex]t=\frac{ \frac{1}{0.250M}-\frac{1}{0.850M}}{0.002387M^{-1}min^{-1}}\\\\t= 1183min[/tex]

For the second part, we proceed by using the same rate constant and the new initial concentration as follows:

[tex]\frac{1}{[A]} =\frac{1}{[A]_0} +kt\\\\\frac{1}{[A]} =\frac{1}{0.750M} +0.680M^{-1}min^{-1}*0.996min\\\\\frac{1}{[A]} =1.99,M[/tex]

[tex][A]=0.50M[/tex]

14. In this case, according to the units of the rate constant, we infer this is a zeroth-order reaction, therefore we compute the half-life has shown below:

[tex]t_{1/2}=\frac{[A]_0}{2k}[/tex]

Thus, we plug in to obtain:

[tex]t_{1/2}=\frac{2.696x10^{-6}M}{2*50.5M*hr^{-1}}[/tex]

[tex]t_{1/2}=2.67x10^{-8}hr[/tex]

Best regards!

Answer:

I'm pretty sure its the one that says very little at the beginning but if I get it wrong I'm sorry

Answer:

44.45 g of tetrahydrofuran.

Explanation:

From the question given above, the following data were obtained:

Volume of tetrahydrofuran = 50 mL

Density of tetrahydrofuran = 0.889 g/mL

Mass of tetrahydrofuran =?

Density of a substance is simply defined as the mass of the substance per unit volume of the substance. Mathematically, density is expressed as shown below:

Density = mass / volume

With the above formula, we shall determine the mass of tetrahydrofuran needed. This can be obtained as follow:

Volume of tetrahydrofuran = 50 mL

Density of tetrahydrofuran = 0.889 g/mL

Mass of tetrahydrofuran =?

Density = mass / volume

0.889 = mass / 50

Cross multiply

Mass = 0.889 × 50

Mass of tetrahydrofuran = 44.45 g

Therefore, the student should weigh out 44.45 g of tetrahydrofuran.

Answer:

1.24 kJ is required to convert 14 g of liquid from 43.5°C to 128.2°C

Explanation:

This is a typical calorimetry problem:

We have to assume, no heat is lost to sourrounding.

First of all, we need to go from 43.5°C to 97.4°C, the boiling point.

Q = Ce . m . ΔT

We replace data, 1.18° J/g . 14 g . (97.4°C - 43.5°C)

Heat for the first stage is: 890.4 Joules

Now we have to change the state, and we need the ΔH. As we do not have latent heat, we can proceed like this:

1 mol release 30.1 kJ at vaporization.

We convert the mass to moles → 14 g.  1mol/ 67.44g = 0.207 mol

0.207 mol will release (0.207 . 30.1 kJ) = 6.25 kJ

Now, we are at gaseous phase.

Q = Ce . m . ΔT → 0.792 J/g°C . 14g . (128.2°C - 97.4°C)

Q = 341.5 Joules

To determine the amount of heat, we sum all the obtained values:

890.4 Joules + 6250 Joules + 341.5 Joules = 1238.2 J

We convert to kJ →  1238.2 J . 1kJ / 1000J = 1.24 kJ

The heat required to convert 14.0 g of an unknown liquid at 43.5 °C to gas at 128.2 °C is 7.48 kJ.

We want to calculate the heat required to convert 14.0 g of an unknown liquid at 43.5 °C to gas at 128.2 °C.

We can divide this process in 3 steps.

We will calculate the heat for this step (Q₁) using the following expression.

Q₁ = c(l) × m × ΔT

Q₁ = (1.18 J/g･°C) × 14.0 g × (97.4 °C - 43.5 °C) = 890 J = 0.890 kJ

where,

We will calculate the heat for this step (Q₂) using the following expression.

Q₂ = (m/M) × ΔHvap

Q₂ = [14.0 g/(67.44 g/mol)] × 30.1 kJ/mol = 6.25 kJ

where,

We will calculate the heat for this step (Q₃) using the following expression.

Q₃ = c(g) × m × ΔT

Q₃ = (0.792 J/g･°C) × 14.0 g × (128.2 °C - 97.4 °C) = 342 J = 0.342 kJ

where,

Q = Q₁ + Q₂ + Q₃ = 0.890 kJ + 6.25 kJ + 0.342 kJ = 7.48 kJ

The heat required to convert 14.0 g of an unknown liquid at 43.5 °C to gas at 128.2 °C is 7.48 kJ.

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Answer:

It would get colder

Explanation:

The lattice energy is the energy involved in the disruption of interactions between the ions of the salt. In this case, we have: ΔHlat  = 350 kJ/mol > 0, so it is an endothermic process (the energy is absorbed).

The solvation energy is the energy involved in forming interactions between water molecules and the ions of the salt. In this case, we have: ΔHsolv  = 320 kJ/mol > 0, so it is an endothermic process (the energy is absorbed).

The dissolution process involve both processes: the disruption of ion-ion interactions of the salt and the solvation process. Thus, the enthalphy change (ΔHsol) in the preparation of the solution is calculated as the addition of the lattice energy and solvation energy:

ΔHsol= ΔHlat + ΔHsolv = 350 kJ/mol + 320 kJ/mol = 370 kJ/mol

370 kJ/mol > 0 ⇒ endothermic process

Since the preparation of the solution is an endothermic process, it will absorb energy from the surroundings, so the solution would get colder.

Answer:

Car B has more inertia than Car A

Explanation:

Given that,

Mass of car A = 1500 kg

Mass of car B = 2000 kg

Inertia is directly proportional to the mass of an object. Inertia is the measure of the mass of an object.

In this case, the mass of car B is more than that of car A, it means the inertia of car B is more than that of car A.

Hence, the correct option is (c) "Car B has more inertia than Car A".

Answer:

Cu2 + 4 NH3 = Cu (NH3) 42+

so - - >

[Cu (NH3) 6] ^ 2+

Explanation:

Answer:

50 g of S are needed

Explanation:

To star this, we begin from the reaction:

S(s) + O₂ (g) →  SO₂ (g)

If we burn 1 mol of sulfur with 1 mol of oxygen, we can produce 1 mol of sulfur dioxide. In conclussion, ratio is 1:1.

According to stoichiometry, we can determine the moles of sulfur dioxide produced.

100 g. 1mol / 64.06g = 1.56 moles

This 1.56 moles were orginated by the same amount of S, according to stoichiometry.

Let's convert the moles to mass

1.56 mol . 32.06g / mol = 50 g

Answer:

Lava, magma (molten rock) emerging as a liquid onto Earth's surface. The term lava is also used for the solidified rock formed by the cooling of a molten lava flow.

Explanation:

1.53 mol CO₂

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

9.24 × 10²³ molecules CO₂

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

1.53437 mol CO₂ ≈ 1.53 mol CO₂

Answer: soaps are a sodium or potassium salts of long chain fatty acids.when triglycerides in fat/oil react with aqueous NaOH or KOH,they are converted into soap and glycerol.This is called alkaline hydrolysis of esters.Since this reaction leads to formation of soap, it is called the saponification process.

Explanation:

Answer:

they are a lot tougher and are expecting only greatness, sort of like theater critiques.

Explanation:

Answer:

definite volume

Explanation:

Both solids and liquids have a definite volume: The difference is that solids have definite shape while liquids do not -liquids take the shape of their containers-.

Having a definite volume is why liquids cannot be compressed, a property that is used in hydraulic systems.