Objects, materials and their properties. Read, watch float and sink, sort, then play.
What it is
Things we use are objects, and the stuff they are made from is a material. A chair is an object, and it may be made from the material wood.
Why it works
One object can be made from different materials, and one material can make many objects, so we keep the two ideas separate.
Why it matters
This helps us describe and choose the right material for each object.
A few examples
A spoon (object) can be made of steel or wood (materials). A bag can be made of cloth or plastic.
What it is
Materials differ in how light passes through them. Transparent materials let us see through clearly, translucent ones let some light through hazily, and opaque ones let none through.
Why it works
Light either passes, partly passes, or is blocked, which is why we can see through glass, dimly through butter paper, and not at all through wood.
Why it matters
This is why windows are glass and doors are wood.
A few examples
Clear glass is transparent. Butter paper is translucent. Wood is opaque.
What it is
Dropped in water, some materials float and others sink, depending on the material and its shape.
Why it works
Light materials like cork and dry wood tend to float, while dense ones like iron and stone sink, a pattern we can test and predict.
Why it matters
This matters for boats, swimming aids and many everyday choices.
A few examples
Cork and wood float. Coins and stones sink.
What it is
Some materials dissolve in water and seem to vanish into it, while others do not dissolve and stay separate.
Why it works
When a material dissolves, its tiny bits spread evenly through the water. Sugar and salt do this, but sand and chalk do not.
Why it matters
This helps us understand mixtures and how to make and separate them.
A few examples
Sugar and salt dissolve in water. Sand and chalk powder do not.
What it is
We can test any object by placing it gently in water and watching whether it floats or sinks.
Why it works
The result depends on the material, so testing groups objects into floaters and sinkers, building our sense of which materials are light or heavy for their size.
Why it matters
Simple water tests like this are real science we can do at home.
A few examples
A plastic ball floats. An iron nail sinks. A dry leaf floats.
What it is
Materials are grouped by properties: shine (lustre), hardness, whether they float, dissolve, or let light through.
Why it works
Sorting by properties helps us compare materials and pick the best one for a job, like hard metal for tools or soft cotton for clothes.
Why it matters
This is exactly how a scientist studies materials.
A few examples
Metals are shiny and hard. A sponge is soft. Wood is opaque and floats.
Drop things in water: light materials bob at the top, heavy ones rest at the bottom.
Drag each into transparent, translucent or opaque. sorted 0/6
Have a go first, then tap to see the clear steps.
Q1. Is a chair an object or a material?
Q2. Can you see clearly through frosted (butter) paper?
Q3. Does salt dissolve in water?
Q4. Will a cork float or sink in water?
Q5. A polished metal spoon is shiny. This shine is called...
Q6. Name one property we can use to group materials.