Physical Properties of Matter (TEKS 5.6A)
Name three physical properties you can test or measure to classify a block of wood and an iron nail.
Mass, volume, magnetism, physical state (solid), ability to conduct thermal/electrical energy, or solubility.
Which state of matter expands to completely fill the size and shape of any closed container it is placed in?
GAS
What happens to the physical properties of individual substances (like iron filings and sand) when they are mixed together without dissolving?
They maintain (keep) their original physical properties.
What is a solution? Give one common classroom example.
A special type of mixture where one or more substances dissolve evenly into another (e.g., salt water, lemonade, sugar water).
A student tests four unknown solids (A, B, C, D) for magnetism and solubility. Solid C is attracted to a magnet and does not dissolve in water. What is Solid C likely made of?
Iron (or a magnetic metal like nickel/cobalt).
A student places a solid sphere into a container of water with a density of 1.0 The sphere sinks directly to the bottom. What can you conclude about the relative density of the sphere?
The sphere is more dense than water
A student inflates a party balloon with air until it becomes firm. How does this demonstrate that air is made of matter?
Air has mass and takes up space (volume), pushing against the inside walls of the balloon as gas particles fill the container.
You mix glass marbles, iron paperclips, and wooden beads in a bowl. Which physical property would you use to separate the paperclips quickly from the rest?
Magnetism
When salt dissolves in water to form a solution, which physical property changes and which physical property is maintained?
State/appearance changes (salt disappear from view), while properties like taste and total mass are maintained.
Think about this setup: A copper wire is wrapped around an iron nail and connected to a battery. What energy transformations and properties are being tested here?
Electrical energy flowing through a conductor creates an electromagnet; tests electrical conductivity and magnetism.
A student connects a copper wire, a rubber band, a plastic spoon, and an aluminum foil strip into a circuit with a light bulb one at a time. Which materials will cause the light bulb to turn on, and why?
Copper wire and aluminum foil, because metals are good conductors of electricity.
Describe the arrangement and movement of particles in a solid compared to a liquid.
In a solid, particles are tightly packed in a fixed position and vibrate in place. In a liquid, particles are close together but can slide past one another.
A mixture contains sand, salt, and water. Describe a two-step process to separate all three components.
Step 1 Use a filter/screen to separate the insoluble sand from the saltwater. Step 2: Evaporate the water so the salt is left behind.
Name two ways to increase the rate at which sugar dissolves in a beaker of water.
Stir the liquid, heat the water, or crush the sugar into smaller particles.
A student measures 50 mL of water in a graduated cylinder. After dropping a marble inside, the water level rises to 62 mL. What is the volume of the marble?
12mL (or 12 cm3) using liquid displacement (62 - 50)
Explain how water is the reference point when testing the relative density of different objects.
Objects that float are less dense than water, while objects that sink are more dense than water.
How can you prove that matter is made of particles that are too small to be seen using a syringe filled with air?
If you plug the end of the syringe and push the plunger, the trapped air compresses, showing that invisible gas particles are present and taking up space inside.
Why is a mixture of trail mix (raisins, peanuts, chocolate chips) classified as a simple mixture rather than a solution?
The ingredients do not dissolve, are easily separated physical components, and maintain all of their individual physical properties.
If 5 grams of salt is dissolved in 100 grams of water, what will the mass of the resulting salt solution be? Explain your reasoning.
105 grams. Mass is conserved during dissolving because no matter was added or destroyed.
Why does a closed container filled with water weigh the same before and after the water is frozen into ice, even though the ice expands?
The amount of matter (number of particles/mass) remains constant even though the volume increases and density decreases.
A teacher places 10 grams of sugar into 100 mL of warm water and stirs until it can no longer be seen. Has the sugar disappeared? Explain using physical properties.
No, the sugar dissolved (solubility). It separated into particles too small to see, but it is still present in the solution (the liquid retains the sugar's mass and taste).
Draw or describe a particle model showing what happens to water particles when liquid water evaporates into water vapor.
The particles gain thermal energy, move faster, and spread far apart from one another, transitioning from a liquid layout to a loosely spread gas layout without changing the identity of the water molecules.
A student combines 15 grams of iron filings with 25 grams of sand. What is the total mass of the mixture, and what property of the iron allows it to be separated from the sand?
Answer: Total mass is 40 grams 15 g + 25 g. The property is magnetism (iron is magnetic, sand is not).
A student makes tea by dissolving instant tea powder in hot water. How can the original tea powder be recovered from the liquid solution
Evaporate or boil away the water, leaving the dry tea powder/solutes behind at the bottom of the container.
A student wants to separate a mixture of salt, iron filings, sand, and water. Place the following steps in the correct order:
Filter the sand from the liquid.
Use a magnet to remove the iron filings.
Evaporate the water to leave the salt.
Step 2 (magnet), then Step 1 (filter sand), then Step 3 (evaporate water).