Lesson 6

• states of matter
• Middelbare school
• havo, vwo
• Leerjaar 1

This lesson

• The four atom models
  
• The both model
• Time to work on exercises

Learning goals

• Name the four models that describe atoms.

• Explain how the Rutherford experiment shows that the Thomson model is not correct.

•  Describe the key features of the Bohr model.

Class rules

• We sit according to the class plan..
  

• Class mode — You pay attention to the teacher, one person talks.

• Working mode — Working independently, talking quietly.

• No shouting, talking, joking or gesturing to the other side of the class.

• Disturb the class, you go outside.
  

What are atoms?

The evolution of our understanding of the atom

What are the four theories that describe atoms called?

The four main atomic models

• Dalton (1808)
  
• Thomson (1904)
  
• Rutherford (1911)
  
• Bohr (1913)
  

Dalton

• Everything is made up out fundamental building blocks: Atoms
  
• Atoms are indivisible (cannot be split in two)
  
• There are many types of atoms (elements)
  
• Atoms of the same elements have the same mass
  

Thomson

Plum pudding model

Thomson

Plum pudding model

• A blob of positive and negative charges
  

The Rutherford experiment

Rutherford model

Rutherford model

An atom is

• A nucleus containing protons and neutrons
  
• With a cloud of electrons around it 
  

The Bohr model

The Bohr model

• An atom has a nucleus — made up out of protons and Neutrons
  
• Electrons orbit around the nucleus in fixed orbits

The Bohr model

• An atom has a nucleus — made up out of protons and Neutrons
  
• Electrons orbit around the nucleus in fixed orbits

So an atom is made up out of:

The Bohr model

• An atom has a nucleus — made up out of protons and Neutrons
  
• Electrons orbit around the nucleus in fixed orbits

So an atom is made up out of:

• Protons (positive charge)

The Bohr model

• An atom has a nucleus — made up out of protons and Neutrons
  
• Electrons orbit around the nucleus in fixed orbits

So an atom is made up out of:

• Protons (positive charge)
• Neutrons (neutral charge)

The Bohr model

• An atom has a nucleus — made up out of protons and Neutrons
  
• Electrons orbit around the nucleus in fixed orbits

So an atom is made up out of:

• Protons (positive charge)
• Neutrons (neutral charge)
• Electrons (negative charge)

The Bohr model

Simulation

After the Bohr model?

Charge cloud model

Working independently

Link

Learning goals

• Describe the Dalton model, the Thomson model, the Rutherford model and the Bohr model
  
•  Explain how the Rutherford experiment shows that the Thomson model is not correct
•  Describe the key features of the Bohr model

Learning goals

• Name the four models that describe atoms.

• Explain how the Rutherford experiment shows that the Thomson model is not correct.

•  Describe the key features of the Bohr model.