Complete the passage to describe how electrons are represented in electron dot diagrams. The maximum number of dots an electron dot diagram can have is( A:two, B:Four, C:Six, D:Eight) The maximum number of dots drawn on a side of a chemical symbol in an electron dot diagram is ( A:two, B:Four, C:Six, D:Eight)

so one liter is about 2. something gallons so at 12.8 km/l you would get about 30 mpg which is insane but yeah

Answer: The mileage rating of the car is 30.05 miles per gallon

Explanation:

We are given:

Mileage rating = 12.8 km/L

To convert this level into milligrams per deciliters, we use the conversion factor:

1 mile = 1.61 km

1 gallon = 3.78 L

Converting the above rating into miles per gallon, we get:

[tex]\Rightarrow (\frac{12.8km}{L})\times (\frac{1mile}{1.61km})\times (\frac{3.78L}{1 gallon})\\\\\Rightarrow 30.05miles/gallon[/tex]

Hence, the mileage rating of the car is 30.05 miles per gallon

1) Endothermic reactions:

a) The reaction between ammonium nitrate and water absorbs heat from the surrounding environment.

There are two types of reaction: endothermic reaction (chemical reaction that absorbs more energy than it releases) and exothermic reaction (chemical reaction that releases more energy than it absorbs).

b) Ammonium chloride dissolved in a beaker of water makes the beaker cold.

Dissolving this salt absorbs heat from beaker.

c) Water separates on hydrogen and oxygen when an electric current is run through it.

Electrolysis of water is the decomposition reaction (heat is required), because from one molecule (water) two molecules (hydrogen and oxygen) are produced. Water is separated into two molecules.

2) Exothermic reactions:

a) Three drops of concetrated sulfuric acid added to 100 milliliters in a beaker makes the beaker hot.

Energy is released, beaker absorbs that heat.

b) Uranium atoms are split to produce nuclear energy.

Nuclear energy is released.

c) Methane and oxygen are combined to produce methanol and heat.

Balanced chemical reaction: 2CH₄ + O₂ → 2CH₃OH + heat.

I think the correct answer from the choices listed above would be the last option. If a decrease in temperature accompanies a reaction, then energy was absorbed which means that the reaction is endothermic. Hope this answers the question. Have a nice day.

Answer:

It should be  endothermic reaction.

Explanation:

Because it absorbs more energy than release it.

I took the test before.  

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Chemical Reactions Learning for quiz Unit 3 Lesson 2 Physics

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that is called the Gulf Stream

question answered by

(jacemorris04)

The total number of atoms in 0.290g of P2O5 is approximately 8.6 x 10^22.

To find the total number of atoms in 0.290 g of P2O5, we need to first calculate the number of moles in the given mass. The molecular weight of P2O5 (Phosphorous pentoxide) is approximately 141.94 g/mol (2(30.97 g/mol for P) + 5(16.00 g/mol for O)). This allows us to calculate the moles: 0.290 g / 141.94 g/mol = 0.00204 mol of P2O5.

Since each molecule of P2O5 contains 7 atoms (2 P atoms and 5 O atoms), the number of atoms in one mole will be 7 x Avogadro's number (6.022 x 10^23). Therefore, for 0.00204 mol of P2O5, the total number of atoms will be 0.00204 mol  x 7 x 6.022 x 10^23 = 8.6 x10^22 atoms.

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The molecular formula is C₄H₈O.

We must calculate the masses of C, H, and O from the masses given.

Mass of C = 17.873 mg CO₂ × (12.01 mg C/44.01 mg CO₂) = 4.8774 mg C

Mass of H = 7.316 mg H₂O × (2.016 mg H/18.02 mg H₂O) = 0.818 48 mg H

Mass of O = Mass of compound - Mass of C - Mass of H

= (7.321 – 4.8774 – 0.818 48) mg = 1.6251 mg

Now, we must convert these masses to moles and find their ratios.

From here on, I like to summarize the calculations in a table.

Element     m/mg      n/mmol     Ratio    Integers  

     C          4.877 4    0.406 11   3.9984         4

     H         0.818 48   0.811 99   7.9944         8

     O         1.625 1      0.101 57   1                    1

The empirical formula is C₄H₈O.

Answer: a) [tex]Frequency=666\times10^{12}Hz-789\times10^{12}Hz[/tex]

b) [tex]Wavelength=380nm-450nm[/tex]

Explanation: Visible light is a form of electromagnetic wave.

Wavelength is defined as the distance between two successive crests of a wave. It is represented as symbol [tex]\lambda[/tex].

Frequency is defined as the number of complete cycles happening per second. It is represented by the symbol [tex]\nu[/tex].

Wavelength and Frequency follow inverse relation,

                                              [tex]\nu=\frac{c}{\lambda}[/tex]

where, c = speed of light = [tex]3\times10^8m/s[/tex]

Wavelength and frequency of a wave is usually expressed in a range.

a)  [tex]\text{Frequency of visible light}=666\times10^{12}Hz-789\times10^{12}Hz[/tex]

b) [tex]\text{Wavelength of visible light}=380nm-450nm[/tex]

The predicted order of ionization energies is Li > Na > K > Rb

Atomic size increases as you go down a Group (see image). We are adding electrons to increasingly larger shells.

The valence electrons are further from the attraction of the nucleus, so they are less tightly held.

Thus, Li has the highest ionization energy and Rb the lowest.

The calculation results in a specific heat of approximately 1.89 J/g°C.

To calculate the specific heat of the tires we first find the amount of heat absorbed by the brakes when they cool down.

Using the formula Q = mcΔT:
Heat absorbed by brakes Q = (90.7 kg)(1.400 J/g°C)(312°C)

Note that 1 kg = 1000 g, so we convert the mass of brakes from kg to grams.

Q = (90700 g)(1.400 J/g°C)(312°C) = 39930720 J

This same amount of heat is transferred to the tires. We can now calculate the specific heat of the tires.

Q = mcΔT, where m is mass, c is specific heat, and ΔT is the temperature change.

Rearranging the formula to solve for specific heat c:

c = Q / (mΔT)

Substituting Q = 39930720 J, m = 123000 g (since tires are 123 kg), and ΔT = 172°C:

c = 39930720 J / (123000 g * 172°C)

c = 39930720 J / 21156000 g°C

c = 1.89 J/g°C

The specific heat of the tires is approximately 1.89 J/g°C.

Answer: Homogeneous mixture

Explanation:

Element: It is a substance made up from only one type of atom. It is not a mixture.

Heterogeneous mixture: This is a mixture having two or more substances that are unevenly distributed. The substances can be easily separated.

Homogeneous mixture: This is a mixture having two or more substances that are evenly distributed. These cannot be easily separated. The substances retain their original properties.

Compound: It is a substance which is composed of two or more elements in a specific ratio. these are evenly distributed but in this the elements do not retain their original properties.

Hence, from the above points, it is easily justified that homogeneous mixtures are the ones, where the particles are evenly distributed and also retain their original properties.

I'm pretty sure the strongest metal known to man is Tungsten.

You are right! That is true.

Hello!

Atomic Number, is the number where the atom lays on the perodic table and can be found through the number of protons. Meaning that gallium has an atomic number of 31 !

Atomic weight, which is equal to 70 in this case, can be found by subtracting the atomic number from that total to find the remaining number of neutrons that make up the mass. So gallium has 31 protons and 39 protons.

Hope this helps answer your question.

Answer: The correct answer is 31.

Explanation:

Atomic number is defined as the number of protons or electrons that are present in a neutral atom.

Atomic number = number of protons = number of electrons

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons

We are given:

Number of protons = 31

Mass number = 70

Number of neutrons = Mass number - Number of protons = 70 - 31 = 39

Atomic number will be equal to the number of protons present in an atom which is 31

Hence, the correct answer is 31.

Hello!

To find the number of moles that are in the given amount, we need to divide the total number of atoms by Avogadro's number, which is 1 mole is equal to 6.02 x 10^23 atoms.

5.0 x 10^25 / 6.02 x 10^23 ≈ 83.0564

Therefore, there are about 83.06 moles of iron (sigfig: 83 moles).

To solve this, first add 9 on both sides.

8x-9+9=8+9

8x=17

Then divide both sides by 8 to find the value of x.

[tex]\frac{8x}{8}[/tex]=[tex]\frac{17}{8}[/tex]

x=[tex]\frac{17}{8}[/tex]

The final answer is x=[tex]\frac{17}{8}[/tex] or 2.125.

Making lemonade is a chemical change because once the ingredients are mixed together they cannot be seperated.

Making lemonade is a chemical change.

In a physical change, the composition of the substance does not change. For example, if you melt a piece of ice, the ice changes from a solid to a liquid, but the water molecules that make up the ice are still the same.

In a chemical change, the composition of the substance does change. For example, when you make lemonade, you are combining sugar, lemon juice, and water to create a new substance with different properties. The sugar and lemon juice molecules react with each other to form new molecules of sucrose and citric acid.

Learn more about chemical change at:

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A chemical property of iron is its ability to combine with oxygen to form iron oxide, commonly known as rust; this process is known as corrosion. Therefore, the correct answer is that iron combines readily with oxygen "C".

The question asks about the chemical property of iron. Chemical properties describe the ability of a substance to undergo a specific chemical change. For iron, a key chemical property is its capability to combine with oxygen to form iron oxide, commonly known as rust. This process is part of a broader category of chemical changes known as corrosion. Unlike physical properties, which can be observed without changing the substance, chemical properties can only be seen as the substance is transformed into a different substance. Therefore, the correct answer to the question is C) Iron combines readily with oxygen.

Hey there!

Values Ka1 and Ka2 :

Ka1 => 8.0*10⁻⁵

Ka2 => 1.6*10⁻¹²

H2A + H2O -------> H3O⁺  + HA⁻

 Ka2 is very less so I am not considering that dissociation.

Now Ka = 8.0*10⁻⁵ = [H3O⁺] [HA⁻] / [H2A]

lets concentration of H3O⁺  = X then above equation will be

8.0*10−5 = [x] [x] / [0.28 -x

8.0*10−5 = x² /  [0.28 -x ]

x² + 8.0*10⁻⁵x  - 2.24 * 10⁻⁵

solve the quardratic equation

X =0.004693 M

pH = -log[H⁺]

pH = - log [ 0.004693 ]

pH = 2.3285

Hope that helps!

The first one is 206 then move, body, then protects, calcium,strong,blobs

C. A compound !hope this helps!

Im pretty sure the answer is C. a compound

c = f*L 

If you cant remember this just consider the units of each (denoted [c] is units of c): 

[c] = meters/second, [f] = 1/seconds or Hertz, [L] = meters 

So [c] = [f*L], an easy way to remember it. 

So to get the frequency, just solve for f: 

f = c/L = (3.00 x 10^8)/(5.93 x 10^-7) m/s = 5.05902192 × 10^14 m/s ~ 5.06 x 10^14 m/s 

Carbon Monoxide would be the correct answer.

Answer: A. vegetables, meat, chicken

B. insects, fruits, seeds

Explanation:

A primary consumer is the trophic level in the food chain, which feeds upon the plants and other autotrophs. It includes all the herbivorous animals.

A secondary consumer is the trophic level in the food chain, which feeds upon the herbivorous animals. They are carnivores.

A and B are the two correct options. A will feed upon both plant and animal products such as vegetables and meat, and chicken respectively.

Also B also consumes over the plant products such as fruits and seeds and insects.  

Organisms A (omnivore consuming vegetables, meat, chicken) and B (eating insects, fruits, seeds) function as both primary and secondary consumers in a food web. They consume both producers like plants and other consumers like insects.

The commonly eaten foods of the organisms listed determine whether they are considered primary consumers, secondary consumers, or both. Organism A is an omnivore, consuming both plants and animals, making it both a primary and a secondary consumer. Organism B, which eats insects, fruits, and seeds, could also be considered both primary and secondary since it consumes plants and animals (insects). Organism C, which eats grasses, barks, twigs, and acorns, is primarily a primary consumer. Finally, Organism D, which eats other animals (ladybugs, caterpillars, flies, mosquitoes), is a secondary consumer.

Considering the options provided and the definitions of primary and secondary consumers, the correct pairing that identifies which organisms are both primary and secondary consumers is A and B. Organism C is only a primary consumer, and Organism D is only a secondary consumer.

the decay of the neutrons in the nucleus of the atom

The process of radiometric dating uses the decay of uranium-238 to lead-206 to determine the age of ancient rocks.

U-238 decays to stable Pb-206 largely by the emission of α particles, with a half-life of about 4.5 × 10⁹ a.

Thus, geologists can determine the age of rocks by measuring the relative amounts of U-238 and Pb-206.

However, the method is not “exact”.

The rock must be more than ten million years old so that enough uranium can decay to make the amount of lead measurable.

The age uncertainty for 100-million-year-old rocks ranges from 100 000 a

to 3 000 000 a.

The error margin for older rocks, say, 2.5 billion years old, can be as low

as 2 000 000 a. That’s a long time, but it’s an uncertainty of less than 0.1 %.

Explanation:

Elements of group 1 represented in the blue column are alkali metals.

Elements of group 2 represented in the peach column are alkaline earth metals.

Elements from scandium to zinc or all the elements represented in the green columns are transition metals.

Elements in coral pink boxes represent metalloids, that is, they show properties of both metals and non-metals.

Elements present in blue, peach, green and coral pink boxes are all metals.

Whereas elements present in pink, that is, group 18 are all noble gases.

And elements present in yellow boxes are all non-metals.

The Ideal Gas Law allows us to assume that at constant volume the variation in pressure is proportional to the variation in temperature.

Hence,

[tex]\frac{P1}{T1} = \frac{P2}{T2}\\ \\

\frac{4.50}{200} =\frac{P2}{250} \\ \\

P2 = \frac{4.50 * 250}{200}\\ \\

P2 = 5.63 atm[/tex]

Using Gay-Lussac's Law,  we get [tex]P_2[/tex]  [tex]5.625 atm[/tex] at [tex]250 K[/tex].

To find the new pressure of a gas at constant volume when the temperature changes, we use Gay-Lussac's Law, which states that pressure is directly proportional to temperature for a given mass of gas at constant volume. The formula for Gay-Lussac's Law is:

[tex]\frac{P_1}{T_1} = \frac{P_2}{T_2}[/tex]

Where:

Given:

[tex]P_1 = 4.50 \, \text{atm}[/tex]

[tex]T_1 = 200 \, \text{K}[/tex]

[tex]T_2 = 250 \, \text{K}[/tex]

[tex]P_2 = P_1 \times \frac{T_2}{T_1}[/tex]

[tex]P_2 = 4.50 \, \text{atm} \times \frac{250 \, \text{K}}{200 \, \text{K}}[/tex]

[tex]P_2 = 4.50 \, \text{atm} \times 1.25 \\ \implies P_2= 5.625 \, \text{atm}[/tex]

The new pressure of the gas at [tex]250 K[/tex] will be [tex]5.625 atm[/tex].