Stop 3 of 12 · The path
Periodic table — one map
Every element in one grid. Rows are shells filling; columns (groups) react alike.
Bench tool
Periodic table explorer
Left: metals that give electrons. Right: non-metals that take them. Far right: noble gases, which barely react. Tap any tile:
How it works
- Across a row, protons grow by one. Electrons fill the same shell, pull harder — atoms shrink.
- Down a group, shells grow. Outer electron further out, easier to lose — Group 1 gets fiercer downward.
- The shape predicts joins. Metals left, non-metals right: they trade electrons. That is next stop.
Worked examples
Na vs K. Both Group 1. Potassium fizzes harder — its outer electron is further out.
Cl wants one electron. Group 17, one short of full. That is why it grabs sodium's spare.
Ar does nothing. Full shell already. Noble gases sit out most reactions.
Where it goes wrong
Mass order has exceptions. The table sorts by protons, not mass — argon is heavier than potassium but comes first.
Try it at home: family sort
Card columns. Write Li, Na, K, Mg, Ca, F, Cl, He on cards and sort them into columns by behaviour you remember. Lookalikes land together — the table groups behaviour, not alphabet or weight.
For teachers
Learners read the table like a number grid — probe by asking why potassium sits under sodium. Quickest check: point at fluorine and ask them to predict chlorine's behaviour from position alone.