2.2 Periodic table

• Scheikunde
• Middelbare school
• havo
• Leerjaar 3

Periodic table and molecular formulas

Learning goals

At the end of the lesson you:

• Know the name of 40 atoms and their symbols
• Can write a chemical formula
• Know the name of 40 elements and their formulas
• Know the name of 17 compounds and their formulas
• Know the place and name of four groups in the periodic table
• Know that groups in the periodic table have similar properties

Periodic Table of Elements

• 1869: Dimitri Mendelejev
• Elements ordered by mass and similar poperties
• Predicted non-discoverd elements 

Symbols

Each kind of atoM has its own symbol.

First letter always capital letter.

Second letter always a

lower case letter. 

H  = hydrogen
He = helium

Special groups

Group 1: Alkali metals

Group 2: Alkanline earth metals

Group 17: Halogens

Group 18: Noble gasses

Molecular formula

Atoms shown as spheres with symbol

Cl

H

H

O

O

C

C

O

H

Molecular formula

CO₂                                                                                                          

 

C

O

O

H

H

O

Index: shows the number of atoms (at the bottom right of the symbol)

H₂O

Molecular formula

Multiple molecules are shown with the coëfficiënt. This number comes before the molecar formula.

C

O

O

C

C

C

C

O

O

O

O

O

O

O

O

The coëfficiënt is 5, so 5CO₂

What was the basis of the order Mendelejev used for the known elements?

1. Color
2. Mass
3. Date of discovery
4. Name

What do elements in the same group have in common?

1. Mass
2. Date of discovery
3. Chemical properties
4. Being metal or non-metal

How many atoms do you see?

1. 5
2. 10
3. 15
4. 0

How many kind of atoms do you see?

1. 3
2. 2
3. 5
4. 0

How many molecules do you see?

1. 15
2. 2
3. 5
4. 1

Wat is the coëfficient in the following formula?

3CH​4​​

1. 4
2. 1
3. 3
4. 0

How many H-atoms are there in the following formula?

3CH​4​​

1. 4
2. 1
3. 3
4. 12

Give out List of substances

Assign test of List of substances

Making exercises

Make 16+20 (10 min in silence)

Finished? Make 14, 15, 17 - 19, 21, 22, 24- 26

Making exercises

Make 22+24 (10 min in silence)

Finished? Make 14, 15, 17 - 19, 21, 25, 26

Reflection

At the end of the lesson you:

• Know the name of 40 atoms and their symbols
• Can write a chemical formula
• Know the name of 40 elements and their formulas
• Know the name of 17 compounds and their formulas
• Know the place and name of four groups in the periodic table
• Know that groups in the periodic table have similar properties