# Lesson Notes By Weeks and Term - Senior Secondary 1

Crystal structure

Term: 3rd Term

Week: 3

Class: Senior Secondary School 1

Age: 15 years

Duration: 40 minutes of 5 periods each

Date:

Subject:      Physics

Topic:-       Crystal structure

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Define crystals
2. State the types of crystals and give examples of each type
3. Differentiate between crystalline and amorphous substances

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

 PRESENTATION TEACHER’S ACTIVITY STUDENT’S ACTIVITY STEP 1 INTRODUCTION The teacher reviews the previous lesson on the Hooke’s law Students pay attention STEP 2 EXPLANATION He defines and explains crystals. He states the types of crystals and gives examples of each Students pay attention and participates STEP 3 DEMONSTRATION He explains the differences between crystalline and amorphous substances Students pay attention and participate STEP 4 NOTE TAKING The teacher writes a summarized note on the board The students copy the note in their books

NOTE

CRYSTAL STRUCTURE

Crystal is a piece of solid matter which has its atoms, molecules or ions arranged in a highly regular repeating pattern or lattice. Solids are divided into Crystalline and non-crystalline or amorphous substance examples of crystalline substance are: Sodium Chloride, Diamond, copper (II) tetraoxosulphate (IV) etc.

Non Crystalline or Amorphous Substance are solids that does not have their molecules arranged in a regular pattern, they are mostly in liquids e.g. Sulphur, Graphite etc.

DIFFERENCES BETWEEN CRYSTALLINE AND ARMORPHOUS SUBSTANCES

 S/N CRYSTALLINE SUBSTANCES ARMORPHOUS SUBSTANCES 1 They have definite shape They have no definite shape 2 They have definite Boiling and Melting Point They have no definite Boiling and Melting Point 3 They are soluble in Polar Solvents They are not soluble in Polar Solvents 4 They can exist either in hydrated or anhydrous form They exist only in anhydrous form

EVALUATION:   1. Define crystals

1. State the types of crystals, giving two examples of each
2. Outline three differences between crystalline and amorphous substances

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively