material properties
Which material is hard and can scratch wood: metal, rubber, or paper?
metal
What is the first thing we check when testing if a material is waterproof?
Whether water passes through it or not.
Group these materials into natural or man-made: wood, plastic, cotton, glass.
Natural: wood, cotton | Man-made: plastic, glass
Name one material used to make windows.
glass
I am soft, can be stretched, and used in clothing. Who am I?
cotton or fabric
Name a material that changes shape when you bend it but returns to its original shape.
rubbber
How can you test whether a material is flexible without breaking it?
By bending or twisting it carefully.
Sort these materials by texture: sandpaper, silk, rubber ball, metal spoon.
Rough: sandpaper | Smooth: silk, rubber ball, metal spoon
Why is plastic often used for water bottles instead of metal?
Plastic is light, cheaper, and does not rust.
I am clear, hard, and often used in windows. Who am I?
glass
Why do we test if a material floats or sinks before using it for a boat?
To know if it can stay on water or will sink.
You want to use a material to make a playground slide. What tests would you do before choosing it?
Check if it is smooth, strong, safe, and can slide easily.
You have 5 objects: a rubber band, a rock, a feather, a glass cup, a sponge. Which property can you use to group them?
Hardness or softness. Hard: rock, glass cup | Soft: feather, sponge, rubber band
If you want to make a cooking pot, which property is most important in choosing the material and why?
Heat conductivity, because the pot needs to get hot quickly and cook food.
I float on water, am lightweight, and used for packing. Who am I?
foam
You have two materials: one is shiny and smooth, the other is rough and dull. Predict which one will heat up faster under sunlight and explain.
he shiny and smooth one will heat up slower because it reflects sunlight, while the rough and dull one absorbs sunlight and heats faster.
If a material stretches a lot before breaking, what property is being tested?
Flexibility or elasticity.
Look at 3 objects: aluminum foil, paper, clay. Decide which could be used to hold water and explain why.
Aluminum foil and clay, because they are waterproof or can form a container. Paper cannot hold water.
Some shoes have rubber soles. Predict what would happen if the soles were made of metal.
They would be slippery, heavy, and unsafe to walk in.
I am strong, not bendable, and used to build bridges. Who am I?
steel or concrete
Explain why some materials feel soft but can still be very strong. Give an example.
Because softness does not always mean weakness; for example, rubber is soft but strong and can stretch without breaking.
Design a simple test to see which of two materials is stronger. Describe the steps clearly.
Try bending, pulling, or pressing both materials carefully and see which one breaks first. The one that withstands more force is stronger.
You are given 4 unknown materials. How would you group them without touching them, just by looking?
Group them by color, shine, or shape.
You are building a treehouse. Choose 2 materials and explain why you picked them based on their properties.
Wood (strong and safe) and rope (flexible and strong for holding parts together).
I am sticky, can hold papers together, but I am not glue. Who am I?
tape