---
name: intro_chemistry
description: Teaches chemistry basics to a beginner or builds a short chemistry lesson plan: the periodic table as a map, what happens in a chemical reaction, where energy comes from, and safe kitchen-counter experiments. Triggers on requests like "explain the periodic table", "teach me chemistry", "simple chemistry experiments", "plan a science lesson", or any beginner chemistry tutoring.
metadata: { "includeInPrompt": true }
---

# Intro Chemistry

## Purpose

Give a beginner a real foundation in chemistry, or draft one as a lesson. The arc runs: what atoms are, the periodic table as a map of the elements, how atoms trade partners in reactions, where energy comes from, and a hands-on experiment to make it stick. It works for kids with adult supervision, teens, and adults starting from zero.

## Workflow

1. **Gauge the level.** Ask one question if it is not obvious: age range or "kid with adult, teen, or adult learner?" Adjust depth only, never the facts.

2. **Teach in this order.** Do not jump ahead:
   - Atoms and elements: one element = atoms with the same number of protons (the atomic number). An element is a pure substance; compounds are two or more elements chemically joined.
   - The periodic table as a map: 118 known elements, arranged by increasing atomic number into 7 rows (periods) and 18 columns (groups). Elements in a group behave alike. Metals on the left, nonmetals on the right, noble gases (group 18) mostly keep to themselves. Full map walkthrough lives in `references/periodic-table.md`.
   - Chemical reactions: atoms rearrange into new molecules. Nothing is created or destroyed (conservation of mass, Lavoisier, late 1700s), so equations must balance: same count of each atom on both sides. Work the example `2H2 + O2 -> 2H2O` by hand and show why `H2 + O2 -> H2O` fails.
   - Energy: breaking bonds takes energy in, forming bonds gives energy out. Reactions that give out more than they take in are exothermic (burning methane); reactions that need more than they give out are endothermic (photosynthesis). Full treatment in `references/reactions-and-energy.md`.
   - An experiment: pick one from `references/experiments.md` and run the full protocol with the learner, predicting before observing.

3. **Every term gets a one-sentence definition the first time it appears.** No jargon left hanging. Say "bond" before "breaking bonds".

4. **Predict, then observe.** For every experiment, ask the learner to predict what will happen before it runs. Afterward, connect what they saw to the chemistry: which bonds broke, which formed, where the energy went.

## Output Contract

- Plain language, short paragraphs, one idea per paragraph.
- Every factual claim matches `references/` or the sources listed there. Never invent dates, numbers, or quotes.
- Worked examples show every step, not just the answer. Equations are balanced in full.
- Any experiment plan includes the safety checklist from `references/safety.md` up front, not buried at the end.
- Terms defined on first use. No rhetorical questions followed by their own answer, no filler transitions.

## Operating Rules

1. Safety first, always: every experiment suggestion carries the checklist from `references/safety.md`. Never suggest open flames, stove heating, or mixing household chemicals beyond the listed food-grade experiments. Never suggest mixing bleach with acids or ammonia.
2. Keep the periodic table accurate: 118 elements, ordered by atomic number (protons), 7 periods, 18 groups. Do not present Mendeleev's original ordering (by atomic mass) as the modern one; name it as history when used.
3. Balancing rule: coefficients can change, subscripts never can. State this every time an equation is balanced.
4. Do not overclaim what an equation says: a balanced equation gives relative amounts of atoms and molecules, not how fast the reaction runs or whether it needs a push.
5. Kid-safe framing: for young learners, "atoms are like LEGO bricks" is fine as analogy, but follow it with the real definition.
6. No em dashes. No hype language ("game-changer", "supercharge", "unlock"). If a sentence sounds like a motivational poster, rewrite it.