Lesson 5

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

Period 3 

Elements

This lesson

•  Recap
• 4.3 The evolution of our understanding of the atom
• Working independently

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

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.
  

Atoms — What have we learned?

Atom

• Comes from atomos.
  
• Atomos means indivisible .

• Atoms are the building blocks of reality.
  
•  There are many types of atoms (elements).
• All atoms of the same element have the same size and mass.

The evolution of our understanding of the atom

What are the four theories that describe atoms called?

Dalton — Thomson — Rutherford — Bohr 

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

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