Physical Science

What this covers

• Describing and sorting materials by measurable properties: mass, volume, hardness, flexibility, magnetic attraction, whether it conducts electricity, and whether it floats
• Solids, liquids, and gases, including evidence that gases are real matter with weight, and what happens to particles during melting, freezing, evaporation, and condensation
• Telling apart changes that can be reversed (melting, dissolving, freezing) from changes that form new substances (burning, rusting, baking, mixing vinegar and baking soda)
• Conservation of matter: showing that total weight stays the same when sugar dissolves or ice melts in a sealed container
• Separating mixtures and solutions using sieving, filtering, evaporation, and a magnet, and deciding which method fits which mixture
• Building and troubleshooting a simple circuit, and testing which materials let electric current pass through
• Measuring temperature and describing heat moving from warmer objects to cooler ones, including insulators and conductors

Where learners get stuck

Thinking dissolved sugar or evaporated water has 'disappeared' or been destroyed

Students trust their eyes, and when something stops being visible it feels gone. They usually have no mental picture of particles too small to see, so weighing a sealed jar before and after is what makes the idea click.

Using 'melting' for any change caused by heat, including a candle burning or an egg cooking

Everyday speech is loose with the word, and both changes involve heat. The fix is asking a single question each time: can you get the original material back?

Believing cold is a substance that moves into an object, so a coat 'makes' you warm and a thermos 'keeps cold in'

It matches how it feels and how people talk. Reframing every case as heat moving from warmer to cooler — and insulators just slowing that movement — resolves a whole cluster of later confusions.

Assuming heavy things sink and light things float, judged by how heavy the object feels in the hand

Weight is the obvious property to notice; the comparison to an equal volume of water is not. Comparing a small pebble to a large block of wood forces the issue.

What a session looks like

A session runs as spoken back-and-forth. Evelyn poses a situation — a puddle that vanished from the playground, a bulb that won't light, salt stirred into warm water — and asks the student to predict what will happen and say why. The student explains in their own words; Evelyn follows up on the reasoning rather than just the answer, and asks for the evidence that would settle a disagreement. Where a hands-on test would help, she describes a version using kitchen items so it can be tried between sessions. Vocabulary like evaporation, solution, conductor, and reversible is introduced after the student has described the idea in plain language.

Helpful to know first

• Reading a thermometer and a scale, and using a ruler in centimetres
• Comparing numbers and doing simple addition and subtraction to check whether weights match
• Sorting objects into groups and explaining the rule used
• Writing or dictating what was observed, separately from what it means

Questions

What does my child need to know about states of matter in 4th grade?

That solids, liquids, and gases are all made of particles too small to see, that heating and cooling move a material between those states, and that gases such as air have weight and take up space. Naming the changes — melting, freezing, evaporation, condensation — and giving a real example of each is the usual expectation.

How do I explain physical versus chemical change to a 10-year-old?

Ask whether you can get the starting material back. Melted chocolate can be re-solidified, so it's a physical change. Burnt toast cannot be un-burnt and smells different, so a new substance has formed. Signs of a new substance include bubbling, colour change, a new smell, or heat being given off.

Do you do experiments in an online science session?

Evelyn describes simple tests using household materials and talks the student through predicting, observing, and explaining, but there is no lab equipment and no supervision of anything involving heat, flame, or chemicals. Most of the session is reasoning about what would happen and why.

My child can define the vocabulary but can't answer 'why' questions on tests. What helps?

Definitions memorised on their own don't transfer. Sessions spend most of the time on explanation questions — why the outside of a cold glass gets wet, why the weight didn't change when the sugar dissolved — so the student practises linking a term to an observation instead of reciting it.