# Transition elements in the periodic table

> Where they are, how many, and the two classes


## Objectives

- Locate the transition elements in the middle of the long form of the periodic table, between the (s) and (p) blocks.
- State that they include more than 60 elements, i.e. more than half the number of known elements.
- Classify them into main transition elements (d-block) and inner transition elements (f-block: lanthanides and actinides).

## 1. The transition elements and their series




## 2. Just a few metals?

Predict: how many transition elements are there?

- About 20
- About 10: the famous metals
- More than 60: more than half of the known elements ✓

There are more than 60 transition elements, more than half the number of known elements. They fill the middle of the table between the (s) and (p) blocks, plus the two separate rows at the bottom.

[ar-EG] الـ transition elements أكتر من 60 عنصر، يعني أكتر من نص عدد العناصر المعروفة. هي مالية نص الجدول بين الـ (s) والـ (p) blocks، ومعاه الصفين المنفصلين اللي تحت.
## 3. In the middle of the table

Remember: the (s) and (p) blocks are on both sides of the long form of the table. The transition elements: the middle of the table and the two rows at the bottom **The transition elements** occupy the middle of the periodic table between the (s) and (p) blocks. They include more than 60 elements, i.e. more than half the number of known elements. So they're not a small club. They're the biggest part of the table.


## 4. Explore the table

Tap each highlighted element and read its block. Which ones are transition elements? Ca, Fe, Ag, Nd, U and Ga Ca: s-block. Not a transition element. Fe and Ag: d-block, in the middle. Transition elements. Nd and U: f-block, the two rows at the bottom. Nd is a **lanthanide** and U is an **actinide**. Transition elements too. Ga: p-block. Not a transition element.


## 5. Two classes

These elements can be classified into: 1- **Main transition elements**. 2- **Inner transition elements**. We'll study the main transition elements only. Main transition elements The **d-block**: the middle of the main table. Inner transition elements The **f-block**: the two rows at the bottom, the **lanthanides** and the **actinides**. Inner transition elements (f-block): the lanthanides and the actinides Lanthanides and actinides are main transition elements, like the d-block ones.


## 6. Main, inner or neither?

Tap the table to check where each element is. Then sort. Sort each element.


## 7. A new case

Element X is in period 5. It sits between strontium (group IIA, 2) and indium (group IIIA, 13). What is X?

- An inner transition element (f-block)
- A representative element of the p-block
- A main transition element (d-block) ✓
- A representative element of the s-block

X is a main transition element. In period 5, the d-block lies between the s-block, which ends at Sr (group IIA), and the p-block, which starts at In (group IIIA).

[ar-EG] الـ X ده main transition element. في الـ period 5، الـ d-block بيقع بين الـ s-block اللي بيخلص عند الـ Sr (الـ group IIA)، والـ p-block اللي بيبدأ من الـ In (الـ group IIIA).
## 8. Summary

Transition elements occupy the middle of the periodic table between the (s) and (p) blocks. They include more than 60 elements, i.e. more than half the number of known elements. Main transition elements (d-block) and inner transition elements (f-block: lanthanides and actinides). Transition elements: **more than 60 elements**, in the **middle** of the periodic table **between the (s) and (p) blocks**; classified into **main** and **inner** transition elements. Can you explain why 'transition elements are a few famous metals' is wrong? They include **more than 60 elements**, i.e. more than half the number of known elements: the whole middle of the table (d-block) plus the two rows at the bottom (f-block).



Chapter: Transition Elements (https://yaani.ai/ar/learn/chemistry/chem-s3-en.ch1)
Source: https://yaani.ai/ar/lesson/chem-s3-en.lesson-te.position-in-periodic-table