The intern taught a top-performing class, and the parents wanted to change the homeroom teacher.

After handling the matter, Lu Qian first returned to the math group to retrieve the test papers from the last quiz, and then returned to Class 25.

Standing on the podium, Lu Qian flipped through the test papers. "The results of the last quiz are out. You did well. You were steady and solid, and you didn't lose any points on the basic questions. Very good. I knew you guys could do it."

Come on, give yourself a big pat on the back.

As he spoke, Lu Qian started clapping himself.

Amidst laughter, the whole class began to applaud enthusiastically.

"Xie Tianming, another perfect score, excellent! Worthy of praise."

"Li Kewei has made great progress, and he got a perfect score this time! Very good! He deserves praise."

"Let's give them a round of applause."

The whole class erupted in another gasp and applause.

It's one thing for Xie Tianming to get a perfect score, but Li Kewei is starting to act like a monster too!

The whole class knew that these quizzes tested the knowledge they had just learned, and that as long as they listened in class, they could definitely get high scores.

However, there is also a challenging question that tests their logical thinking skills.

Surprisingly, a second person actually did it.

"Cough cough cough cough!" Li Jun pressed his neck and coughed repeatedly at Li Kewei, while making faces at the same time.

That's really powerful!

He knew perfectly well why he got a perfect score!

Li Kewei sat upright, his eyes fixed straight ahead, not daring to meet Li Jun's gaze at all; the moment he did, he would lose his composure.

"Come on, you two, come up here and hand out the papers." Lu Qian divided the papers into two stacks.

rub!

The two stood up at the same time and walked arrogantly to the podium.

Cool!

"I told you a few days ago, if you did well on the quiz, I'll carve an ice ball for you and give you chilled drinks as a small reward." Lu Qian went to the refrigerator, took out the ice that had been frozen in a special mold, and placed it on the prepared large tray.

At the same time, they took out the ice cubes from the freezer.

Lu Qian poured the ice out of the mold; some of it was crystal clear, while some was white and misty. Then he poured out the ice cubes from the ice cube tray.

"Crystal-clear ice and hazy white ice are both ice, so why does this happen?"

As he asked the question, he put on gloves, took a tool, chipped off a piece of ice, measured the diameter against the glass, and began to carve an ice ball.

The students below the stage answered in a cacophony of voices.

"Is it because the water is different?"

"I know that, transparent ice is because the water is cleaner!"

"The mineral water must be frozen."

"..."

Lu Qian nodded. "Some students are right about part of it. Simply put, it is relatively clean, without impurities or air bubbles."

"The crystal-clear ice cubes are made by freezing boiled water, but even so, there are still some impurities and air bubbles inside."

"If you freeze it directly, there will still be some air bubbles, and it won't achieve a crystal clear effect."

Why?

"Putting water directly in the refrigerator to freeze, with cold air all around, the water freezes from the outside. The freezing speed is too fast, and the small air bubbles and impurities inside don't have time to escape before freezing, so it forms a hazy white ice."

"The mold utilizes the principle of heat preservation, with the top directly exposed to cold air, allowing the water to freeze from top to bottom, rather than freezing from all sides. This way, the ice on top can gradually squeeze out air bubbles and impurities, thus achieving a crystal-clear appearance."

The whole class suddenly realized.

Lu Qian continued chiseling ice. He quite enjoyed chatting with his students from time to time about real-life phenomena and sharing some interesting tidbits of knowledge.

"You've managed to freeze crystal-clear ice, but do you know how much energy is involved in freezing water?"

"Pipes burst in winter because water freezes and expands. Currently, there is nothing we can access that can stop water from freezing and expanding; it will either explode or be squeezed and deformed."

"I don't know if you've ever tried this, but when I was in elementary school, it was quite cold in my hometown. I left a sealed aluminum can outside, and it exploded in the middle of the night. People who didn't know better would have thought someone had set off a firecracker."

The whole class burst into laughter.

As they were talking, Lu Qian finished carving out the two ice balls. They weren't perfectly curved, but the light reflected from their edges and corners was even more crystal clear.

"You two perfect scorers, would you prefer iced tea or something else?" Lu Qian asked with a smile as he placed the ice puck into the glass.

"Guojiao! It has to be Guojiao!" Li Kewei shouted.

"I want Guojiao too!" Xie Tianming shouted back.

"Okay!" Lu Qian nodded readily and poured himself a glass of chilled iced tea.

A light brown liquid poured onto an ice puck greatly increases its value.

These small daily rewards can make learning less tedious, and Lu Qian thinks they are meaningful.

Xie Tianming and Li Kewei stood tall and straight, picked up their glasses, looked at each other simultaneously, and gently clinked glasses.

"Cheers!"

Then they each took a sip.

"Hmm~" Xie Tianming's eyes lit up, "Ninety-nine percent, a rare find~"

Li Kewei squinted, feeling as if he were already wearing a tuxedo and had become a well-known figure in the industry.

The whole class burst into laughter.

"Let's continue talking about water freezing." Lu Qian drew water molecules arranged in hexagons on the blackboard. "Suppose we have an incredibly strong container that can stop this expansion force and allow the water to continue freezing. After the water freezes into part of the ice, it will turn into another kind of ice. In this case, the volume of the water will not increase, but will shrink, forming high-pressure ice."

The students in the audience exclaimed "Wow!"

"Could this be the ancient ice from the novel?"

"Huh? Is it the one that the Heavenly Dream Ice Silkworm ate?"

Do we have them on our planet?

Lu Qian continued, "They don't exist in the natural environment; they're mainly hidden deep within planets, but they can also exist on other planets where conditions are suitable."

"In reality, large laboratories can also make this kind of special ice. I wonder if any of our students will be able to see this kind of ice in the future. If you do, remember to come back and share it with your teacher."

After lightening the mood for a while, Lu Qian looked up again and asked, "Where's Li Jun? My Jun, where are you?"

"Here it is! Here it is!" Li Jun stood up abruptly.

Lu Qian said, "I just asked Director Pan about your question yesterday about whether we could perform archery at the New Year's Eve party."

"Huh?!" Li Jun perked up.

"Can!"

"yeah!"

"Of course, you're only allowed to bring bows and arrows on New Year's Eve, and you'll need to sign a safety agreement," Lu Qian said. "You can decide what to perform yourself."

Li Jun's eyes lit up, and he looked directly at Fan Siwen.

Fan Siwen: "?"

"You can't use real people as targets!" Lu Qian directly exposed his little scheme.

Li Jun: "Teacher Lu, you have a really good eye for people!"

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