dtnovels Chapter 901
Chapter 901
"The so-called condensation nucleus does not refer to a single thing, it is a general term, and most substances can be condensation nuclei."
Having said that, Wei Wu reached out and picked up the piece of ice on the podium.
"For example, this piece of ice can be considered a condensation nucleus, primarily providing a fulcrum and attachment points."
"The snowflakes that drift down from the sky in the cold winter months are formed when water vapor in the air attaches to dust particles."
"Rivers freeze because the water is flowing, and there are substances like gravel and dust in the water that act as condensation nuclei."
"If there are no condensation nuclei, then water will not be able to naturally solidify into crystals even in a low-temperature environment."
As he spoke, Wei Wu opened the thermal box again and took out the remaining two-thirds of the bottle of water and held it in his hand.
"So-called supercooled water, to put it simply, is water that has had impurities removed, making it purer. It's also called purified water!"
"Without impurities to act as condensation nuclei, water cannot freeze into ice and can remain liquid even at low temperatures."
"But the water is in an unstable state at this point. If you give it a little help, it will immediately transform into a metastable state."
As Wei Wu spoke, he stretched out his hand, pointed his finger at the bottle and flicked it. There was a slight bang, and a magical scene appeared instantly.
The water, which was originally in liquid state, solidified little by little and finally turned into solid state after being flicked by the finger.
Seeing this magical scene, all the craftsmen present were dumbfounded, and even the quiet breathing in the classroom could be heard.
But soon someone came to his senses and even forgot to raise his hand, and couldn't wait to ask.
"Mr. Vice President, you said that water cannot freeze without condensation nuclei, but just now you said that this water is pure water without condensation nuclei."
"If there are no condensation nuclei, then how does the water freeze? Isn't this a bit contradictory?"
When Wei Wu heard this question, he was not angry at all because of the questioning, but was particularly happy.
Science requires a spirit of questioning because it is the core driving force of scientific progress. Of course, this does not mean that we should question everything indiscriminately.
Instead, it is based on rational thinking, reflecting on existing views, questioning and testing their correctness.
So after the craftsman questioned it, Wei Wu immediately praised him:
"It's great that you thought of this. We need a questioning and dialectical spirit to make progress in studying science."
"As for your question, my answer is that although this water is pure, it does not mean that it does not have condensation nuclei."
"Remember when I flicked the bottle just now? In addition to solid particles, small bubbles in the water can also serve as condensation nuclei."
"As long as the unstable state of supercooled water is destroyed, small bubbles and surface defects of the container will be treated as condensation nuclei!"
After the experiment was completed, the craftsmen were once again shocked by Wei Wu, and Xu Miao, the first disciple, almost knelt down.
At this moment, Wei Wu was a saint radiating light in his eyes, and the name of that light was knowledge!
After teaching craftsmen for a long time, Wei Wu had long been accustomed to their inexperienced appearance.
As for his first disciple Xu Miao, although his eyes were a little too passionate, Wei Wu believed that he would get used to it soon.
Now that the supercooled water experiment has been completed and a lot of knowledge has been explained to the craftsmen, it is time to start class.
However, just as Wei Wu was thinking about what to say today, he suddenly remembered that there was one thing he had not explained.
So under everyone's gaze, Wei Wu turned his head again to look at Sun Chang.
"Sun Chang, can you spare some extra manpower? There's something I might need them to do."
Hearing Wei Wu's words, Sun Chang was about to nod and speak, but Song Zhong on the side spoke first: