5th grade · Science · Unit 4 of 10
Physical or Chemical?
Changes that make new things
What your child practices
Telling a physical change from a chemical change, spotting the signs of a new substance, and how making and throwing away everyday products affects the environment.
Minnesota K-12 Academic Standards benchmark: 5P.1.2.1.1 · physical and chemical changes, and when a new substance forms
How we explain it
Children can open this short lesson before they practice.
- A physical change alters size, shape or state, but no new substance is made.
- Melting, crushing, cutting and dissolving are physical changes.
- A chemical change makes a new substance, like rusting or burning.
- Signs of a chemical change: gas bubbles, a new smell, color change or light and heat.
Example: Wood burns and turns to ash and smoke. Physical or chemical change? Ash and smoke are new substances. New substances mean a chemical change. Answer: chemical change
Physical or Chemical? in Minnesota
In the Minnesota K-12 Academic Standards, this is unit 4 of 10 in 5th grade Science, after Changes of State and before Measuring Matter.
Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
Iron turns reddish-brown rust. This is a…
- physical change
- change of state
- chemical change
chemical change
Hint: Rust is a new substance.
Question 2
Which is a chemical change?
- Freezing bread
- Baking bread dough
- Cutting bread
Baking bread dough
Hint: Baking creates new substances that were not in the dough.
Question 3
A student crushes a can. This is a…
- physical change
- change of state
- chemical change
physical change
Hint: The shape changed, but it is still the same metal.
Question 4
A banana peel turns brown. What kind of change is this?
- Change of state
- Physical change
- Chemical change
Chemical change
Hint: A color change that you cannot undo shows a new substance.
Question 5
A factory burns fuel to make a product. What is one possible effect of this process on the environment?
- It uses no energy at all
- It always cleans the air
- It can release gases that pollute the air
It can release gases that pollute the air
Hint: Burning fuel can release greenhouse gases and other pollutants.
Question 6
Why is making new aluminum cans from recycled cans better for the environment than from new aluminum?
- It uses much less energy and avoids mining
- It makes the cans heavier
- It uses more water and energy
It uses much less energy and avoids mining
Hint: Recycled metal does not have to be mined and processed from the ground again.