Technology Grade 7: Comprehensive Guide to Material Properties

Course Context and Educational Goals

  • Subject: Technology (Teknik)

  • Target Group: Grade 7 (Åk7)

  • Term: Autumn Term 2026 (HT 2026)

  • Lesson Theme: Material Properties (Lektionstema Materialegenskaper)

Learning Objectives

  • The primary goal is for students to familiarize themselves with various material properties and gain an understanding of how these properties influence the behavior and performance of materials.

  • Another key objective is the acquisition of new vocabulary and concepts specifically related to the fields of construction and technology.

Lesson Content and Practical Discussion

Overview of the Lesson Schedule

  1. Introductory Discussion: The lesson begins with a question designed to spark critical thinking and peer interaction.

  2. Lecture/Walkthrough: A comprehensive review of various material properties.

  3. Visual Learning: The viewing of a short educational film.

Introductory Discussion Prompt

  • Topic: Students are presented with an image featuring different mugs (reference: PLOMUS).

  • Discussion Question: "Which of the mugs in the picture do you think is best, and why?"

  • Activity Format: Students should engage in pair discussions to compare their reasoning and justify their choices based on their intuitive understanding of material and design.

Material Properties: Hardness and Mechanical Strength

Hardness (Hårdhet)

  • Definition: This property defines the extent to which a material is hard or soft.

  • Examples provided:

    • Glass: Cited as an example of a hard material. It is noted that because of its nature, it can break (shatter).

    • Rubber: Cited as an example of a soft material. It has the capacity to bend rather than resist force through rigidity.

Tensile Strength (Draghållfasthet)

  • Definition: This property measures how much a material can be pulled or stretched before it undergoes failure or breakage.

  • Examples provided:

    • Rubber bands: These can be pulled significantly and stretched over long distances.

    • Steel: This material is also noted for its high resistance to pulling forces, being able to withstand significant tensile stress.

Compressive Strength (Tryckhållfasthet)

  • Definition: This property indicates the amount of pressure or weight a material can support without being crushed or collapsing.

  • Examples provided:

    • Brick (Tegelsten): A material that naturally withstands high levels of pressure.

    • Marshmallow: Used as a counter-example, as it is easily crushed under pressure.

Material Properties: Shape Retention and Durability

Elasticity (Elasticitet)

  • Definition: This property demonstrates a material's ability to return to its original form and dimensions after it has been subjected to bending, stretching, or pressing.

  • Example provided:

    • Rubber band: When a rubber band is pulled out and then released, it returns to its initial state as it was before the force was applied.

Plasticity (Plasticitet)

  • Definition: The opposite of elasticity, this property indicates that a material does not return to its original shape after being bent, pressed, or stretched.

  • Examples provided:

    • Playdough (Trolldeg) or Clay (Lera): These materials can be reshaped and molded, but they retain the new form given to them once the force is removed.

Brittleness (Sprödhet)

  • Definition: This property describes how easily a material breaks when it is subjected to pressure, impact (hitting), or bending.

  • Example provided:

    • Glass: Noted as being brittle because it shatters easily when stressed or struck.

Fatigue (Utmattning)

  • Definition: This phenomenon occurs when a material becomes progressively weaker because the same force is applied to it repeatedly over many cycles.

  • Example provided:

    • Metal Wire: If a metal wire is bent back and forth repeatedly, the material will eventually weaken to the point of breaking.

Instructional Media and Assessment Activities

Educational Film: "Properties of Materials"

  • Source: Binogi.se

  • Title: Properties of Materials (Egenskaper hos material)

Assessment and Follow-up

  • Quiz Questions: Immediately following the film, students are required to log into binogi.se to answer the specific quiz questions associated with the video to verify their understanding of the material properties discussed.