Lesson 4.2.2 The Halogens

• Chem
• Secondary Education
• Age 13

Today's Lesson Goals

• identify the key terms about halogens
• formulate a hypothesis 
• analyse experimental data about the properties of halogens
• formulate a conclusion based on the analysis

Scientific Demonstration

Enquiry question: Would you expect bromine to be more reactive than chlorine?

Experiment Results

Understanding key concepts

Are halogens metals or non-metals?

YES

NO

What is the trend in melting points in Group 7? The melting point _______ from top to bottom.

What is the trend in color in Group 7?

1. dark to light
2. light to dark
3. no difference

What is the trend in boiling points in Group 7? The boiling point _______ from top to bottom.

What would predict about the boiling point and melting point of iodine, the next element in Group 7?

1. lower
2. higher
3. same as bromine

Iodine to be _________________ than bromine.

more reactive

less reactive

The electronic structure for bromine is missing from the table. How many electrons do you predict will be in the outer shell?

1. 5
2. 6
3. 7
4. 8

What happens to the size of the atoms as you go down group 7?

1. become smaller
2. become bigger
3. all of the same size
4. disappear

What similarity is there in the structure of these atoms?

1. 1 electron in the outer shell
2. same number of shells
3. 7 electrons in the outer shell
4. no similarity

Suggest why this group is called Group "7".

Collaborative Work