Organising the periodic table

See how Mendeleev's table predicted undiscovered elements and how groups and periods reflect electron arrangement.

⏱ 18 min❓ 8 questions

What you'll be able to do

✔I can explain how Mendeleev organised the elements and why his predictions made his table convincing
✔I can write the electron arrangement of the first 20 elements using the shell model
✔I can relate an element's group and period to its electron arrangement

How this works

1Read the short explanations first — they teach you what you need before each question.
2Answer each question, then tap Check. A right answer moves you on automatically; if it's wrong, you'll see a friendly explanation of why.
3Finish all 3 steps to see your score — sign in and subscribe to unlock the full lesson and save it.

What's inside

8 questions and 1 quick teaching card, including:

✏️Fill in the blank — Type the missing word to complete the sentence.
🔘Multiple choice — Tap the answer you think is best, then check it.

👪Grown-up tip: sit alongside younger learners for the first few lessons. Read the questions together and chat about the explanations — that's where the real learning sticks.

Curriculum: AC9S10U06, AC9S10H01