Which process transfers heat from a hot pavement to a person sitting on it?

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].

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.

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 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 density of Jena’s smoothie is 0.667 g/mL.

Mass = 200 g

Volume = 300 mL

Density = mass/volume = 200 g/300 mL = 0.667 g/mL

Answer:

rounded it is 0.67 g/ml

Explanation: i took the test it was a bit confusing but i figured it out

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.

Formula for water? There is no formula, but there is a symbol, if that's what you meant. The symbol for water is H2O. It means 2 Hydrogen molecules, because the symbol is H. And the O stands for Oxygen. So it meands two hydrogen molecules bonded with one oxygen molecule. Hope I helped :)

Answer:

Explanation:

what do you mean do you mean H2O

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!

Carbon Monoxide would be the correct answer.

The reaction will produce C. 5 mol NH₃.  

N₂ + 3H₂ ⟶ 2NH₃

Moles of NH₃= 7.5 mol H₂ × (2 mol NH₃/3 mol H₂) = 5 mol NH₃

5 moles of ammonia, [tex]NH_3[/tex], can be made from 7.5 moles of [tex]H_2[/tex].

The mole is an SI unit used to measure the amount of any substance. The abbreviation for a mole is mol. One mole is exactly 6.02214076×[tex]10^{23}[/tex] particles.

Given data:

Moles of H₂ react = 7.5 mol

Moles of NH₃ formed =?

Chemical equation:

N₂ + 3H₂       →    2NH₃

Now we will compare the moles of ammonia with hydrogen.

            H₂              :           NH₃

             3               :             2

            7.5             :          [tex]\frac{2 X 7.5}{3}[/tex]  = 5

Hence, 5 moles of ammonia would be formed from 7.5 moles of hydrogen.

Learn more about mole here:

https://brainly.com/question/26416088

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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 %.

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.

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.

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]

that is called the Gulf Stream

question answered by

(jacemorris04)

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.  

You can see my other article just search in search engine with: Learningandassignments diy4pro

Click on my site and find these related article post:

Chemical Reactions Learning for quiz Unit 3 Lesson 2 Physics

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

Answer: The period of the FM wave [tex]1.1299\times 10^{-8} seconds[/tex].

Explanation:

Frequency of the wave = [tex]8.85\times 10^{7} Hertz[/tex]

Frequency is inverse of time period that is :

[tex]Frequency=\frac{1}{\text{Time period}}[/tex]

[tex]\text{time period}=\frac{1}{frequency}[/tex]

[tex]=\frac{1}{8.85\times 10^{7} Hertz}=0.11299\times 10^{-7} seconds=1.1299\times 10^{-8} seconds[/tex]

The period of the FM wave [tex]1.1299\times 10^{-8} seconds[/tex].

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.

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

C. A compound !hope this helps!

Im pretty sure the answer is C. a compound

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

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 

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.