Periodicity

What you'll learn

1. 1

   Imagine a row of cans on a shelf — each one is a different element. As you move along the row, the cans repeat the same pattern over and over!

2. 2

   What does 'periodicity' mean?

3. 3

   Drag the elements into the correct order on the number line — small to big atomic radius.

4. 4

   Let's look at period 2: Lithium → Neon. What happens to atomic radius?

5. 5

   Does atomic radius increase or decrease across a period?

6. 6

   Now look at ionisation energy — the energy needed to remove an electron. Drag the bars to show the pattern across period 2.

7. 7

   Which element in period 2 has the highest ionisation energy?