◆ Materials · Quarter 1
What It Can Do, Not Just What It Looks Like
Some things about a material you can see today. Some you can only find out by waiting.
Two nails and two jars on the desk. Say nothing about them yet. 1 min
Two nails
- Here are two nails from the same box.
- They are the same length, the same colour, the same weight.
- One goes in a dry jar. One goes in a jar of water.
What will be different in one week?
Take three predictions. Write them on the board with the predictor's name. 5 min
You cannot answer that by looking
- Everything you can see about the nail right now is a physical property.
- Grey. Hard. Shiny. 5 centimetres long.
- Whether it rusts is something else.
What is the difference between those two kinds of fact?
Do not give the word yet. Let the class describe the difference first. 4 min
Two kinds of property
Physical propertyWhat the material is like. Colour, hardness, shine, how it bends, whether it floats. You find out by looking, feeling, or measuring.
Chemical propertyWhat the material can become. Whether it burns, rusts, rots, or reacts. You only find out by letting it happen.
Both columns go on the board and stay there all week. 5 min
The four the curriculum names
- Can it be burnt? Paper can. A stone cannot.
- Does it react with other materials? Vinegar and baking soda do.
- Is it degradable? Iron rusts away. Gold does not.
- Is it biodegradable? A banana peel rots. A plastic bag does not.
These four are the guide's own words. Say so. 5 min
How do you know a NEW material was made?
- A colour change that will not wash off
- A gas — bubbles, fizzing, smoke
- Heat or light given off
- A solid appearing in a clear liquid
- And the test that beats all four: can you get the old material back?
Which of these did you see when something burned?
This list is on the wall chart. Point at it. 5 min
The trap
"This food has no chemicals in it."
Is that possible?
Let them argue. Someone will defend the label. That is useful. 3 min
Everything is made of chemicals
- Water is a chemical. So is salt. So is sugar. So is air.
- The word chemical describes what matter is, not where it came from.
- A label saying no chemicals is selling you something, not telling you something.
What might the label be trying to say instead?
The honest reading is usually 'nothing added that we did not name'. 4 min
Undo it, or not
You can undo itIce melts, water freezes. Wax melts, wax hardens. A physical change — the material is the same material.
You cannot undo itPaper burns. A nail rusts. A banana rots. A chemical change — a new material now exists.
Grade 6 goes deeper into this. Today it is only the test. 4 min
Sort these
- Ice melting in a glass
- A match burning
- Bending a spoon
- Milk turning sour
Physical change or chemical change? Show me with one finger or two.
Answers: physical, chemical, physical, chemical. Ask WHY each time. 5 min
Why this matters outside school
- A biodegradable bag is not the same as a recyclable one.
- Burning household plastic releases materials that harm people and living things.
- Rust weakens the roof, the gate, and the jeepney chassis — and a coat of paint stops the air reaching the iron.
Competencies 5, 6 and 7 build on this. Flag it forward. 4 min
Safe handling comes with it
- Never taste a material to test it.
- Never burn anything indoors, and never burn plastic at all.
- Wash hands after handling anything unlabelled.
- If you do not know what it is, do not mix it with anything.
The guide names safe handling in the performance standard. It is not an aside. 3 min
Back to the nails
- They look identical today.
- In one week, one of them will not.
- Nothing you can see right now tells you which.
So what kind of property is rusting?
Chemical. Let the class say it rather than saying it for them. 3 min
This week
- Today — the two kinds of property
- Tuesday — heating changes: wood, coal, sugar
- Wednesday — what to do about harmful changes
- Thursday — set up the investigation properly
- Friday — the weekly check, and the nails
The nails are checked every day and recorded, not opened once on Friday. 2 min
One sentence to leave with
A physical property you can see. A chemical property you have to wait for.
Say it together. It goes on the worksheet and on the wall chart. 2 min