Chapter 432 Chemical Bonding Theory! Shocked the whole audience! Use physics as a sword to carve out the bright future of chemistry!
Ridgway's electron shell model shocked everyone present.
Both physics experts and physics students can understand this theoretical model through his easy-to-understand explanations.
Everyone lamented that mankind's understanding of atoms has gone through a long process.
Now, we are finally about to see the last light.
But Ridgway knew that current shell models were not perfect.
In 1803, Dalton proposed: "Atoms are solid balls and cannot be divided further."
One hundred years later, Thomson discovered that there are electrons in atoms, breaking the authoritative statement that atoms are indivisible.
Next, Li Qiwei proved the existence of atomic nuclei through the experiment of alpha particles impacting gold foil, further expanding people's understanding of atoms.
Later, Bohr proposed the concept of quantization of electron orbits, describing the movement of electrons, which is not arbitrarily moving around the nucleus.
Ridgway added two more quantum numbers to become the current Bohr-Lee model, which can explain various behaviors of electrons.
However, this model still has a flaw, that is, it cannot explain the arrangement of electrons outside the nucleus.
It was not until today that Li Qiwei proposed the shell model of electrons and solved this problem in one fell swoop.
It even revealed a millennium-old mystery in the field of chemistry.
Why elements have different properties.
It can be said that although this theory is still a conjecture, it has conquered everyone present.
Especially driving all the chemists crazy.
It is not only consistent with the derivation of quantum theory in physics, but also consistent with countless experimental phenomena in chemistry.
With such a theory, the probability of making a mistake is too low.
At the same time, this is another example of physics guiding chemistry.
However, the electron shell model is still not perfect.
In real history, after Schrödinger's wave equation was published, physicists discovered that electrons exist in the probabilistic form of "electron clouds".
The shape of the electron cloud is the area where electrons may appear.
At this time, each shell is subdivided into different sub-layers according to different energy levels.
For example, the first shell electron cloud is spherical, so the electron orbit is spherical, called [s orbit].
However, in the second shell, because the number of orbital energy levels has increased, the electron cloud in this layer not only has a spherical shape, but also has a spindle shape.
This spindle-shaped orbit is called a [p orbital].
So, there are s orbitals and p orbitals in the second shell.
In the same way, in the third shell, in addition to s orbitals and p orbitals, there are also [d orbitals].
And so on
Note that the shapes of each orbit here are not made up, but calculated through equations.
With the above knowledge, you can explain:
Why is the electron configuration of argon atoms 2, 8, 8? The last shell is obviously not filled, but it is also a closed shell.
That's what makes tracks.
The electron configuration of argon, written as an orbital configuration, is: 1s②/2s②2p⑥/3s②3p⑥.
1, 2, and 3 represent the number of electron shells, and ② represents the maximum number of electrons that can exist in each subshell.
It can be seen that although there are only 8 electrons in the third layer of argon atoms, they completely fill up the s orbital and p orbital.
Therefore, the remaining sub-shells are just empty shells, and the outer electrons of the argon atom can still be regarded as closed and do not participate in chemical reactions.
Of course, this is under normal circumstances.
As long as the temperature and pressure are high enough, any reaction can occur, and there are many inert gas compounds in later generations.
In real history, when the theoretical system of quantum mechanics matured.
A group of physicists headed by Bohr quickly calculated the situation of each orbit.
Then they didn't go any further, because the rest was all for the chemists.
Then, Pauling, known as the "Einstein of Chemistry", proposed the chemical bond theory. (Chapter 411)
That is, atoms are bonded together through their respective orbits, forming what is called a [chemical bond].
Covalent bonds, ionic bonds, metallic bonds, hydrogen bonds, etc.
Among them, the hybrid orbital theory proposed by Pauling has the most profound influence.
To put it simply, it is an s orbital and a p orbital combined together to form a new hybrid orbital sp orbital.
In the same way, there are sp2 orbitals, sp3 orbitals, etc.
These hybrid orbitals are very conducive to the formation of chemical bonds, allowing chemical reactions to occur.
With the development of chemistry, other orbital theories appeared later, such as molecular orbitals and so on.
However, everything remains unchanged.
The basis of all orbital theories is chemical bond theory.
And this is what Li Qiwei will talk about next.
He wanted to throw out the concept of chemical bonds in advance and become the father of modern chemistry!
Pauling is just 19 years old this year and is still an undergraduate in the United States.
Li Qiwei’s trip to the United States in April, I don’t know if he will be able to see each other.
If he saw him, he would definitely pat Pauling on the shoulder and say to him:
"Xiao Bao, uncle, I like you very much. If I ask you to borrow something, you won't blame uncle."
"A hamburger for you."
Pauling: Listen to me, thank you, because of you.
After smiling, Li Qiwei looked at the people in the audience and said loudly:
"With the electron shell model, we can further think about the nature of chemical reactions."
"Take the reaction of sodium and chlorine to form sodium chloride as an example."
"It is now known that the outermost shell of a sodium atom has 1 electron, and that of a chlorine atom has 7 electrons."
"Because atoms are composed of charged particles, there will be electromagnetic force between atoms, and the intensity of universal gravitation is negligible compared to the electromagnetic force."
"So, when two atoms are close to each other, they will be bonded together due to electromagnetic force."
"I gave this form of bonding between atoms a professional term, called [chemical bond]."
"The physical mechanism of chemical bonding is electromagnetic interaction."
"For sodium chloride, sodium and chlorine exist in the form of sodium ions and chloride ions respectively."
"The chemical bond between them can be called [ionic bond]."
"As for substances such as hydrogen gas, hydrogen atoms exist as neutral atoms."
"They form a closed shell by sharing an electron pair."
As he spoke, Li Qiwei drew a schematic diagram (chemistry is not the focus of this book, so I won’t draw a diagram for you.)
"I call this chemical bond [covalent bond]."
"For metals, you can think of many metal atoms aggregated together."
"The electrons in the outermost shell can break away from the atomic nucleus and move throughout the entire metallic solid."
"I call this chemical bond [metallic bond]."
"Wait."
"I don't know much about chemistry. There may be other types of chemical bonds."
"But it doesn't matter."
"When we introduce the shell model of quantum theory into chemical bond theory, we can analyze the nature of these bonds."
"Thus understanding the nature of each chemical reaction."
"Chemists have now gotten rid of the black box and will no longer know anything about the reactions in glass instruments."
"Of course, detailed and in-depth research is a matter for chemists."
"I won't do anything for you today, and I don't know how to do it."
"As a physicist, my mission has been accomplished."
"The above is the content of my speech today, and I have made a small contribution to chemistry."
"Thank you everyone."
After Li Qiwei finished speaking, the entire venue was audibly quiet.
At this moment, time seemed to be frozen.
Everyone's mouths were open, their eyes were wide open, and their faces were full of shock. Ridgway introduced quantum theory into chemistry and proposed the electron shell model, which explained the nature of the different properties of elements.
This is enough to cause shock.
The chemists present were all in admiration and wished they could kiss Professor Bruce on the spot.
However, the chemical bond theory that followed shocked them even more.
Although it is just a concept and prototype.
But the profound significance contained in it is no less than the subversive effect that the theory of relativity has brought to physics.
With this concept, the research object of chemists is no longer the balance and products of chemical reactions.
It is no longer a matter of weighing the weight changes before and after the reaction. This is a job that even craftsmen can do.
Instead, we go deep into the subtle process of chemical reactions and study everything about the reactions from the source.
How incredible and great this is.
At this moment, chemists seemed to have mastered the code of matter.
All material changes in the universe will be understood, conquered, and applied by humans.
Chemistry, rise!
"God, today's speech will definitely make countless people regret it."
"Such shocking content should be announced in front of all scientists around the world."
"However, Professor Bruce said it so lightly."
"The theory that all chemists admire and shock is just a side-result he came up with while studying quantum theory."
"Just like the by-products in the polymer reaction process."
"This is Professor Bruce's extremely terrifying strength, which simply makes anyone who wants to chase him despair."
"."
There was warm and crazy praise in the venue.
Heisenberg felt like he was surrounded by a ball of fire.
Everyone looked at the man on the stage as if they were worshiping gods.
He is too strong!
A casual strike is an achievement that even a top chemist cannot achieve in his lifetime.
No, you won’t be able to achieve it in ten lifetimes.
But in the eyes of the other party, these are only insignificant contributions.
Heisenberg was trembling all over now.
The light in his eyes almost penetrated the dome of the venue.
He is no longer shy and silent, but is inspired by the primitive wildness in his body.
"Is this the style of the first person in the world?"
"When can I reach this state?"
"God, I must devote all my energy to the study of quantum theory."
"It's so great."
"Just a partial application can change the future of chemistry. Is there anything more incredible than this?"
At this moment, Heisenberg strengthened his determination to study quantum theory.
Only the forefront of quantum theory is the pinnacle battlefield in the world and the place he looks forward to most.
A random soldier on the periphery is a lofty professor in the eyes of ordinary people, a being who cannot be easily contacted.
The center of the battlefield is where the great gods fight.
Any disturbance there will determine the future of mankind.
More than ten years later, Heisenberg understood this truth.
The first person in the world is not only the first in wisdom, but also the first in strength!
Pauli couldn't calm down at this moment.
Li Qiwei's performance has far exceeded his imagination.
As a super genius in the eyes of everyone, Pauli had the aloofness of a genius.
In his opinion, Professor Bruce's power was only due to his early birth.
At that time, modern physics was just beginning, and there were so many unknown theories and phenomena waiting to be discovered that it was completely a blue ocean.
Pauli felt that if he had been placed in that era, he might have been the author of the theory of relativity.
This is the confidence of genius.
"Historical factors account for a large part of Professor Bruce's greatness."
However, today, Li Qiwei's strength shattered Pauli's dream.
Because Pauli not only understood the theory of relativity, he also understood quantum theory.
He could even calculate the orbital data of hydrogen atoms on the spot.
He is now a doctoral student of Professor Sommerfeld, and his doctoral topic is about the hydrogen molecular model.
The existing Bohr-Lee model can well explain the electron orbit of hydrogen atoms.
But facing a hydrogen molecule composed of two hydrogen atoms, there is nothing you can do.
Pauli could not think of a solution.
Now, he has found inspiration in the electron shell model and chemical bond theory.
This huge gap in strength made Pauli understand.
When he and Professor Bruce were on the same starting line, he would be so crushed that he couldn't even see the other's back.
He murmured to himself:
"It's so terrible."
"I'd better not be mean in front of Professor Bruce from now on, otherwise I will only humiliate myself."
"However, there is still a problem with the electron shell model."
"I wonder what Professor Bruce thinks."
Pauli was indeed Pauli, although he did not dare to confront Li Qiwei.
But I still dare to ask questions, with only the purity of science in my heart.
It's just that now is not a good time. He has to wait until the venue is quiet before taking action.
The big guys in the front row were also extremely excited at this moment.
They know that once today's content is announced, it will cause a sensation in the chemical world.
I am afraid that all chemists in the world will regret not listening to this lecture in person.
Professor Bruce revolutionized chemistry!
Einstein felt a little chilly on his back.
He originally thought that what Li Qiwei was talking about would be purely physical.
So there was no big invitation to chemists in Germany.
Almost all of those present today are chemists from the University of Berlin.
They now love Einstein to the core.
However, Einstein was still scared:
"I won't become a public enemy of the chemical community now."
He could already imagine that scene.
Nernst looked at Einstein's worried look and smiled knowingly.
As the only chemistry guru present, only he can deeply understand what today's speech means.
"If we say Lavoisier is the father of modern chemistry."
"Then after today, Bruce will be the father of modern chemistry."
(End of chapter)