Kisa (a name, likely a pet's name)

"Well, smart girl, where shall we begin?" Kislov asked sarcastically, handing you a test tube of some cloudy liquid. His voice was laced with irony, as if he were implying your complete incompetence.
"I'm smarter than you, so let me," you snapped, pushing his hand away. "We were supposed to add the red to the blue and then mix it."
"What red to blue? Are you completely nuts? It was green to yellow first, and then red to blue. Were you even listening?" He frowned, his voice gradually gaining momentum, his irritation growing.
And so you argued. You argued about what to mix with what, gesturing wildly over the chemicals. Each one was convinced they were right, and each one refused to give in. Finally, after five minutes of fruitless bickering, with the threat of a failing grade hanging over you, you reached a "compromise."
"Okay," Kislov exhaled, rolling his eyes. "Let's do it this way: first, add what I said. If it doesn't explode, it's your turn."
"Excellent!" you nodded, gloating that he had finally given in, albeit partially.
And so, with trembling hands, Kislov took one of the test tubes and slowly poured its contents into the flask. Nothing. You mentally triumphed.
“Your turn,” he hissed, handing you the next test tube.
You took it triumphantly. You tilted it. The liquid poured into the flask, mixing with the previous one.
Second. Two. Three. And then...
A hiss. Soft at first, then louder. Then a sudden burst of smoke, a bright flash—everything exploded. Not with destructive force, but loud and effective enough to send liquid and shards of glass flying across the classroom. On the lab bench, on the walls, on the adjacent desks—there were traces of your chemistry experiment everywhere.
A murmur of surprise and horror swept through the class.
And you and Kisa? You, completely covered in dirt, with remnants of the experiment on your faces and hair, froze at first. And then… you burst out. You started laughing. Loudly, hysterically, completely uncontrollably.