29.3 Physical Science

29.3 Physical Science

Quick answer: PECT 0013.7 tests physical science: physical and chemical properties of matter, different forms of energy, and force and motion. Add the elementary cluster that makes those ideas teachable: states of matter; mixtures vs solutions; push/pull, gravity, magnets; sound, light, and heat as energy; simple machines as conceptual tools; and conservation of energy as "energy can change form," not as calculus. Hands-on tests of properties beat a vocabulary packet.

Matter and energy are what the nonliving (and living) world is made of and how it moves and changes. STEELS physical-science ideas and Early Learning Scientific Thinking both want investigation (0013.1–0013.4) of stuff you can push, melt, mix, and light up.

Physical and chemical properties of matter

Matter is anything that has mass and takes up space. Air is matter (a bag of air has mass); ideas are not.

Physical properties can be observed or measured without changing the identity of the substance: color, size, shape, mass, texture, hardness, whether it is solid/liquid/gas, whether it is attracted to a magnet, whether it sinks or floats. Children test these: sort by texture, use a pan balance, try a magnet.

Chemical properties describe how a substance can change into something new: ability to burn, rust, react with vinegar. The evidence of a chemical change at elementary grain is a new substance — rust on a nail, a pancake that will not turn back into batter, gas bubbles that were not there. A physical change keeps the same stuff: ice melting, paper torn, water freezing, salt dissolving (the salt is still salt — you can get it back by evaporating).

Do not require chemical formulas, pH scales, or endothermic-equation signs. Do require that melting is not burning.

States of matter; mixtures and solutions

Pennsylvania children see ice, water, and steam (or breath on a cold window). That is 0013.7, and it previews the water cycle in 0013.8 — keep the boundary: here the scoring target is matter and heat, there it is Earth's water system.

Mixture: two or more materials together that keep their own properties — trail mix, a salad, sand and pebbles. Often separable (fingers, sieve, magnet).

Solution (elementary): a mixture in which one substance dissolves evenly so you no longer see pieces — salt water, lemonade. You cannot pick the salt out with fingers; evaporating the water can leave the salt. Do not require solute/solvent vocabulary in PreK. Grade 3–4 can hear dissolve vs mix chunks. A suspension (muddy water that settles) is optional contrast, not a required term.

Force and motion — push, pull, gravity, magnets

A force is a push or a pull. Forces can start motion, stop it, speed it up, slow it down, or change direction. Motion is a change in position.

Ramps, wagons, and playground slides are the lab. A motion-detector app is optional technology; a stopwatch and chalk marks are enough.

Energy — sound, light, heat, and changing form

Energy is what makes things happen — move, heat up, light up, make sound. Forms at PreK–4:

• Light — from the sun, bulbs; we see; shadows when light is blocked
• Sound — vibration (feel a drum, a throat); louder/softer, higher/lower
• Heat (thermal) — warmer/cooler; heat moves from warmer to cooler at a qualitative grain
• Electrical — circuits at "battery, wire, bulb" grain in Grade 3–4 if you have equipment; otherwise "the outlet powers the lamp"
• Motion (kinetic) — a rolling ball
• Stored — food, a battery, a stretched rubber band — "ready to make something happen"

Conservation of energy at elementary grain: energy can change form; it does not just vanish. A battery-powered bulb: stored/electrical → light + heat. A child sliding: stored at the top of the slide → motion, and friction makes heat. Do not require joules, ΔE, or closed-system proofs. Do shut down "the energy got used up and became nothing."

Simple machines — conceptually

Simple machines help people apply force: they can change the direction of a force or make a job feel easier (spread force over a distance). Names to know, not mechanical-advantage formulas:

A compound machine is two or more combined (scissors = levers + wedges). Grade 4 can hunt machines in the building. PreK uses ramps and see-saws without the taxonomy.

Scenarios

PreK. Water, ice cubes, and "what happens on the heater tray?" States. Pushing vs pulling a wagon. Sorting magnetic vs not.

Grade 2. Ms. Alvarez's class separates a mixture (beans, salt, iron filings) with fingers, water, and a magnet — mixture vs solution when salt water is evaporated on a sunny tray. They make shadows and feel a drum.

Grade 4. Mr. Quinn builds a pulley to lift a bag of books, then traces energy forms in a flashlight. Children test whether foil, wood, and steel are magnetic. They reject "the heat disappeared" when a hot spoon cools — the heat went into the air and their fingers.

Differentiation: Real objects first. Sentence frames: "I pushed, so the ball ___." A switch or larger magnet is an access tool, not a different science target (0013.2).

Exam traps for 0013.7

• Melting = chemical change or burning = physical.
• All metals are magnetic.
• Heavier objects fall faster as the idea you teach.
• Energy is used up and gone.
• Simple-machine formulas or high-school chemistry.
• Animals choose to adapt dumped into a force stem (wrong objective).
• Worksheet definitions with no test of a property.

Plan: "Children will [push, melt, mix, light, listen] to find out [a property / a force's effect / an energy form change]." If they only copied 'matter is stuff,' it is not yet 0013.7.