Archive of Our Own

“You understand minerals and reactions better than most court scholars,” he said. “I assumed you might have an opinion. Are you interested?"

“Well…” Maomao folded her arms into her sleeves, still staring at the glowing blade resting atop the forge. “The problem is not only the iron itself. It’s the way the particles inside it are arranged.”

The head blacksmith frowned immediately. “Particles?”

“Tiny pieces too small to see,” Maomao replied. “Everything is made of them.”

Jinshi, unfortunately, looked fascinated. “And these tiny pieces decide whether a sword breaks?” he asked.

“In a way.” Maomao stepped closer to the worktable, picking up a small lump of raw iron with one hand and a brittle fragment of damaged steel with the other. "Metals are a class of chemical elements that all have a characteristic shiny appearance and are good conductors of heat." (And electricity, but they don't have that in ancient China).

"And why are metals stronger than say, wood?" Jinshi inquired.

"The internal structure. Metals are bonded in such a way. There's an electrostatic force of attraction between a mobile sea of delocalized electrons and the array of positive metal ions, withing a solid metal."

 "Attraction between electrons?"

"No. The attraction is between the negative electrons and the positive ions. Basically, Opposites attract."

Jinshi smiled immediately. "So like you and me-"

GLARE. 

The smile vanished with impressive speed. “My apologies,” he said sheepishly. “Please continue.”

"To make the iron stronger, you would need to combine it with other elements."

"Make a mixture?" The blacksmith asked.

"Sort of, but the correct term would be a compound. You see, A compound is a single substance, that can only be formed by a chemical reaction. It's properties are very different from the original element. And it can only be broken down via chemical reaction." She explained, "Whereas a mixture contain 2 or more substances, that don't chemically change, so they have the same properties the did before. A mixture can be separated physically."

“And this process makes the metal stronger?” Jinshi asked.

“It can.”

"What would we combine them with?"

"Well, we could combine it with a few non-metals, in a process called ionic bonding."

"Ionic bonding? What's that?" Jinshi said, wide eyed.

"When a Non-metal bonds with a metal, they must each have either 2, 8, or 18 or 32 electrons in there outer electronic shell. For example, our basic table salt, or Sodium Chloride. Sodium has an electronic configuration of 2,8,1. Whereas chlorine has an electronic configuration of 2,8,7. It would be easier if sodium gave it's singular one electron in it's third shell to chlorine, rather than chlorine giving 7 to sodium. This way sodium's outer shell is full, having 8 electrons in its second shell, and chlorine's outer shell is also full, having gained one from sodium, becoming stable with 8 electrons in it's third shell. Much like how people prefer full stomachs, atoms prefer to have full shells. Since the sodium gave an electron away it became negatively charged (anion), and chlorine became positively charged (cation). Again, the two opposite charges attract and they form a bond. Think of it as a noble giving away excess gold to gain influence."

The blacksmith rubbed his temples. "I never imagined something as simple as salt was that confusing."

"Yes, on their own, sodium is a highly explosive metal and chlorine is a poisonous gas, but together they form commonly used table salt. Like I said, the chemical properties change in a compound."

"So by forming compounds, we could make our blades more durable in battle." Jinshi nodded. "But what would we combine the iron with."

“Carbon,” Maomao answered immediately. “Adding carbon to iron creates steel. Done correctly, it becomes harder and more durable than ordinary iron.”

“And here I thought apothecaries only studied poisons.”

Maomao gave him a flat look. “Anything becomes poison when the balance is incorrect.”

He smiled, “It seems summoning an apothecary was not a mistake after all.”

***

The following afternoon, Maomao found herself once again being inconvenienced by Jinshi. This time, however, there were no furnaces, soldiers, or blacksmiths involved. Only the quiet rustle of leaves in the inner palace garden and the irritatingly pleasant weather accompanying her unwanted lecture. Maomao sat beneath the shade of a flowering tree, sorting dried herbs into separate piles atop a wooden tray. Across from her, Jinshi rested comfortably beside the pond, sleeves draped elegantly over his knees. He had been quiet for nearly five entire minutes, which wasn't like him at all.

“So,” he said eventually, “I was thinking about yesterday.”

I didn't know he was capable of thinking.

"About what?" She said instead.

"You told us about the bonds between metals. And the bonds between a metal and a non-metal. Is there a bond between two or more non-metals?"

"Yes. It's called covalent bonding. It's when two or more non-metal atoms share electrons to form pairs."

"Share?"

“Because neither atom wants to lose electrons completely,” she explained. “Non-metals hold onto electrons more strongly than metals do. Rather than one stealing from the other, they share so both can become stable.”

"Fascinating."

"It is."

Gaoshun appears behind them. "Master Jinshi, you have been summoned."

Jinshi sighs, "Well, duty calls. Farewell apothecary."

“Goodbye, Master Jinshi.”

He rose reluctantly, silk sleeves brushing against the grass as Gaoshun waited nearby. For a brief moment, Jinshi glanced back toward her before following after him. Maomao watched the ripples spreading across the pond long after he disappeared beyond the garden path.

Annoying man.

(Her hands had stopped sorting herbs several minutes ago)