Solid state physics is also related to chemistry, with a bit of physical and chemical properties.

Physics and chemistry are so annoying, those who study physics are afraid of it, and those who study chemistry are also afraid.

In fact, Shen Qi is also a little stunned, this thing is both material and material, and it is not material and non-material, killing people does not pay for your life, it just wants you to die.

In this question, the sum of the energy of the ionic interaction in the NaCl crystal, Ep, has been given.

When r deviates from r0, Ep deviates from Ep0, and the deviation is U.

Then use x to represent the relative offset, and to get the power series relationship between you and x, you must do a Taylor expansion, that is, use the Taylor expansion of Ep at r0.

It's really torturous, and you have to be able to expand Taylor to do a physics problem, but fortunately, Taylor is very easy to expand...... Shen Qi began to answer questions on the test paper.

The expression for the power series of U(x) is:

U(x)=A0+A1x+A2x^2+A3x^3+……

……

From adiabatic compression, it can be seen that:

1/κ=-V（dp/dV）∣r=r0

…… d^2Ep/dV^2=d/dV(dEp/dr*dr/dV)=……

In the end, m=9.4;α=1.77;am=2.53×10^-109J*m^9.4

I don't know if it's right, it's the only way to go, time is in a hurry, and there are five more questions behind. Shen Qi hurriedly entered the answer to the question in the back.

The fourth question, at first glance, looks sparse and ordinary, Shen Qi thought about it carefully, it was quite terrifying.

"A certain amount of ether is encapsulated in a glass tube, one part in liquid form and the other part in gaseous state. ”

"There are no other impurities in the tube, if the volume in the tube happens to be the critical volume of these ethers, then when it is slowly heated to the critical temperature, the liquid level disappears because there is no difference between the gas and liquid phases......"

Although the first three questions took a lot of time, on the fourth question, Shen Qi was very cautious and carefully reviewed the question stem again.

At this point, Shen Qi had an ominous premonition, and his spine was swishing cold.

It's a liquid, it's a gas, it's critical......

What does this mean?

What does this portend?

Van der Waals gas!

There is no doubt that when it comes to the topic of Fan's gas, it must be a purely materialized question.

Afraid of what comes.

Is it?

It's it!

It shouldn't have come.

But it's already here.

It's still here after all.

Silence, a moment of silence.

Shen Qi had to do it in the shortest possible time.

Solve a problem.

glass tubes.

The proportion of the gas phase and the liquid phase.

How much exactly?

Ether, colorless and transparent.

But it is the life-killing liquid in the materialized rivers and lakes.

Deadly, liquid.

Killing is invisible.

Where there is van der Waals, there are rivers and lakes.

But the most dangerous thing is not liquids.

But.

Coexistence of gas and liquid.

Bg and B1.

Finally, Shen Qi started writing:

Take 1mol of ether, with the change of temperature, the total volume is Vk, and the molar fractions of gas phase and liquid phase are α (T) and β (T), respectively.

αVg+βV1=Vk

When the temperature is T, the saturation vapor pressure is p0, and the equal area method obtains:

∫ upper Vg, lower V1pdv=p0(Vg-V1)

Substituting points to get:

RTlnVg-b/V1-b-a(1/V1-1/Vg)=p0（Vg-V1）

……

From Fan's equation:

……

Ψ Fan's ΦΨ equation swastika complements the swastika

……

Obtained:

Liquid phase B1 = 44.1%

Gas phase Bg=55.9%

In the end, Shen Qi gave his answer, that is, the proportion of liquid phase B1 and gas phase Bg.

After completing the first four questions, it took 2 hours.

There are still four questions left, and Shen Qi only has 1 hour to answer them.

It's not that he doesn't work hard, this exam paper is really difficult.

After completing the three questions of 5, 6, and 7, there is only 10 minutes left for Shen Qi.

At this moment, the contestant in front of Shen Qi put away the stationery, and then raised his hand.

Shen Qi is very familiar with this kind of behavior, he used to do it often and submit the papers in advance.

The invigilator walked up to the classmate in front of Shen Qi and asked softly, "Submit the papers?"

"Yes. This player nodded, he is from Suzhou and Hangzhou No. 2 Middle School, a strong school in eastern Zhejiang Province.

This player from Suzhou and Hangzhou No. 2 Middle School sat in front of Shen Qi, and Shen Qi couldn't ignore it if he wanted to.

Whether it is a number competition or a physical competition, teachers and students who engage in subject competitions have heard of the name of Suzhou and Hangzhou No. 2 Middle School.

is also the second middle school, Shen Qi's Nangang No. 2 Middle School and other Suzhou and Hangzhou No. 2 Middle School can not be compared, the Suzhou and Hangzhou No. 2 Middle School group operation, with rudders everywhere, Nangang No. 2 Middle School just a few acres of land, entertaining themselves.

"Do you like to make friends or not, I'm tired of playing this kind of game for a long time. Shen Qi watched the contestants from Suzhou and Hangzhou No. 2 Middle School hand in their papers and left, and began to review the last question.

The last question is not simple, and it will take a few minutes to read the question carefully.

"In a particle collision experiment, a low-velocity k-meson was observed to interact with a stationary proton p, generating a π+ meson and an unknown x-particle. ”

"It is known that the magnitude of the magnetic induction intensity of the magnetic field B is B=1.70Wb/m^2, and the radius of curvature of the measured π+ meson track is R1=34.0cm. ”

"1. Try to determine the radius of curvature R2 of the x-particle track. ”

"2. Take a look at the following table:

The meter headers are: particle name, symbol, -static mass/MeV+, charge (e)

The specific information for each row is:

Positron, electron;e+,e-;0.511;±1

μ son;μ+,μ-;105.7;±1

π meson;π+,π-;139.6;±1

neutron ;n;939.6;0

λ particles;λ^0;1115.4;0

Negative Σ particles;Σ-;1197.2;-1

Neutral Ξ particles;Ξ^0;1314.3;0

……”

There are more than a dozen rows in the particle list.

The second question is, "What kind of particle is x?"

10 minutes, a total of 10 minutes for reviewing the questions and answering, Shen Qi only has 10 minutes left.

This is for ordinary people, and it is estimated that they will have to give up the answer to the last question.

But Shen Qi didn't give up, and after carefully reviewing the question, he still had 7 minutes left.

This is a topic of modern physics, and the idea of solving the problem should be...... What kind of ideas do you want?,The situation is critical at the moment of the line of fire.,Just masturbate it on the roll!

Shen Qi picked up the pen without thinking.

Taking into account the Lorentz force, the velocity magnitude and mass of the two particles remain the same.

Newton's second law in the form of relativity:

F=d/dt（mv）

……

π+ mesons and x particles move in a circular motion under the action of the Lorentz force, and the radius of rotation is:

R=mv/eB

……

Since m1v1=m2v2 and the absolute value of the charge of the two particles is the same, the radius R2 of the circular path of the particle is the same as that of the circular track of π + meson.

R2 = R1 = 34.0 cm

Shen Qi took 3 minutes to come up with the answer to the first question, the radius of curvature R2 of the x particle track is the same as that of R1 of π + meson, both of which are 34.0cm.

I don't have anyone else who can solve the problem faster, it's faster than the speed of particles...... Shen Qi completed the first question with the speed of a light hand.

There is no way, people are forced out, and in adversity, they may be able to burst out with level 15 combat effectiveness.

I don't believe in this answer myself...... Shen Qi had to believe it if he didn't believe it, there were more than 3 minutes left, he had to complete the second question immediately, and he didn't have time to check the correctness of the first question.

The second question asks Shen Qi to determine what kind of particle x is.

Based on the radius of curvature of x particles R2=R1=34.0cm found in the first question, Shen Qi needs to do some calculations to determine what kind of particle x is.

If the answer to the first question is wrong, the second question must also be wrong.

There's no turning back, there's no time.

Even if the first question is wrong, you have to bite the bullet and make a mistake!

This is Shen Xueba's last stubbornness.

Shen Qi once again showed his light hand speed and powerful mathematical ability, and he calculated directly on the scroll:

v1=eBR1c/root m10^2c^2+e^2B^2R1^2=1.6×10^-19×1.7×0.34×...... m/s

……

Although the time is pressing, Shen Qi still derives and calculates according to the steps he thinks are rigorous and correct, the formula that should be written must be written completely, and the key steps that should be explained in words must be written in a few words, such as "substitution, deletation", which is the basic literacy that a scholar should have.

Substituting, obtains: m20c^2=1196MeV

1196MeV…… Shen Qi crosses the list of particle information on the volume, so x is a Σ-particle?

Jingle bells!

At this time, the handing over bell rang.

Shen Qi pressed the bell and wrote the final answer on the scroll: x is Σ-particle.

It's really the speed of life and death, the speed of life and death in the competition version.

Although it is a hasty submission of papers, there is no time to check, not even a minute of inspection, as a top student, you should also walk out of the examination room calmly and elegantly, which is also the basic quality that a top student needs to have.

Shen Qi walked out of the examination room calmly and elegantly, ah, there was a light rain in the sky, what an unusual day.

"It is very difficult to get a full score in the theory question of the national final, from the preliminary round to the semi-final, from the semi-final to the final, I participated in three physical competition theory exams, and the worst situation may be that I can't get a full score in a theory exam. Shen Qi walked in the light rain, dripping.

"Shen Qi!" Suddenly, a voice came from behind him, and Mu Rong chased after him with an umbrella in his hand.

Mu Rong held an umbrella, and the bottom of the umbrella was just enough to accommodate the teacher and student: "How was the test?"

"I'll hold an umbrella. Shen Qi took the umbrella, he was more than ten centimeters taller than Mu Rong, and Mu Rong struggled to hold the umbrella.

"You seem to be calm. Mu Rong observed Shen Qi's expression.

Shen Qi whispered: "Bamboo canes and shoes are lighter than horses, who is afraid." ”

"A cloud of smoke and rain Ren Pingsheng. Mu Rong immediately took out the next sentence, and then asked cautiously: "Shen Xueba, can you get a full score when you are resurrected with full blood?"