States of Matter
This state of matter has a fixed shape and fixed volume.
Solid.
A change that alters the appearance but not the identity of a substance (for example, cutting or melting).
Physical change
The tiny particles that make up matter are called what?
Particles, atoms, or molecules
The smallest unit of an element that still has the element’s properties is called a(n) what?
Atom
The amount of space an object takes up is called what?
Volume
This state of matter flows to take the shape of its container but keeps the same volume.
Liquid
A change that produces one or more new substances (for example, rusting).
Chemical change
When particles spread from an area of high concentration to low concentration, this process is called what?
Diffusion
A substance made of only one kind of atom is called a(n) what?
Element
The property that describes how much matter is in an object (commonly measured with a balance) is called what?
Mass
Name the state of matter made of particles that move freely and fill any container.
Gas
Is dissolving sugar in water a physical or chemical change? Explain briefly.
Physical change (sugar molecules remain the same; can be recovered by evaporation)
Explain how heating affects particle motion and how that changes the state of matter.
Heating increases particle motion; particles move faster and spread apart — can change solid → liquid → gas.
Give the name of one element commonly found in living things.
Examples: Carbon, Hydrogen, Oxygen, Nitrogen
If you heat a gas in a sealed rigid container, what will happen to pressure and why? (Short explanation appropriate for 5th grade.)
Pressure increases because particles move faster and hit the container walls more often; simple explanation acceptable
Give one example of a substance that can change from solid to liquid at room temperature.
Examples: butter at room temperature (soft solid), chocolate (melts), ice cream melting
Baking a cake causes new substances to form. Is this physical or chemical? Explain one piece of evidence that shows a chemical change occurred.
Chemical change; evidence: new color, bubbling (gas), temperature change, new smell, formation of something that can't easily be separated (accept one or more)
Describe diffusion using the example of perfume sprayed in one corner of a room.
Perfume molecules move from where sprayed (high concentration) to fill the room (low concentration) until evenly mixed.
Explain the difference between an atom and a molecule with an example.
Atom = single particle (e.g., one oxygen atom). Molecule = two or more atoms bonded (e.g., O2 or H2O).
Define density in kid-friendly language and give a simple example (like oil and water).
Density = how much mass is packed into a space; example: oil floats on water because it is less dense.
Describe how particle arrangement and movement differ between solids, liquids, and gases.
Solids: particles tightly packed, vibrate in place
Liquids: particles close but can move/slide past each other
Gases: particles far apart, move freely and fast.
List three signs scientists use to tell that a chemical change has occurred.
Signs: color change, temperature change, gas/bubbles, formation of a precipitate, change is hard to reverse / new substance.
Using particle ideas, explain why a balloon shrinks when placed in a freezer and expands when placed near a heater.
Freezing slows particle motion so they come closer together (balloon shrinks); heating speeds motion so particles push outward (balloon expands).
Draw or describe a simple model showing how two hydrogen atoms and one oxygen atom form a water molecule.
Water = H2O: two H atoms bonded to one O atom (teacher can sketch a simple V-shaped model or accept student description).
Explain conservation of matter in your own words and give a short example from a kitchen experiment (such as mixing or heating).
Conservation of matter: matter is not created or destroyed during a change; example: when water freezes to ice, the total amount of matter stays the same; or in a covered baking experiment, the mass before and after a change remains constant.