Atoms and Matter
What are the tiny building blocks that make up all matter?
Atoms
Name the three common states of matter covered in this unit.
Solid, liquid, gas
What is a physical change? Give one example from everyday life.
Physical change: a change in size, shape, or state without making a new substance (e.g., tearing paper, melting ice).
What is a mixture?
A mixture is a combination of two or more substances that are physically combined.
What is heat doing to particles when a material warms up — are they moving faster or slower?
Define matter in one sentence (include two key properties).
Matter is anything that takes up space and has mass (volume and mass).
Which state of matter has a definite volume but no shape?
Liquid
What is a chemical change? Give one real life example.
Chemical change: when substances react to form new substances (e.g., baking a cake).
What is a heterogeneous mixture? Give one example.
Heterogeneous: parts are visible and not uniform (e.g., salad).
Name one conductor.
What does mass measure about an object?
Mass measures the amount of matter (material) in an object.
Describe how particles are arranged in a solid versus in a gas.
In solids, particles are tightly packed and vibrate in place; in gases, particles are spread out and move quickly.
List three signs that a chemical change may have taken place.
Signs: fizzing (gas), release of heat or light, new smell, color change, explosions
What is a homogeneus mixture? Give two examples.
Name two insulators.
rubber, wood, fabric, etc.
Why air is considered matter even though you cannot always see it?
Air is matter because it takes up space (has volume) and has mass even though its particles are spread out and hard to see.
Give one real-world example of a substance changing from liquid to gas and name the process.
Boiling water becomes water vapor (liquid to gas) — process: evaporation/boiling.
State the Law of Conservation of Matter in one sentence.
Matter cannot be created or destroyed; the total mass stays the same during physical or chemical changes.
True or false: A homogeneus mixture means a chemical change has occured.
Why do materials contract when they get cold?
Their particles stop moving as fast so they get closer together, making the substance contract.
Technically, how many states of matter are there?
Six
Explain why a liquid takes the shape of its container but a solid does not (refer to particle movement).
Liquid particles are close but can move past each other, so they flow to fill the container shape; solid particles are locked in place so the solid keeps its own shape.
A sealed container had a mass of 160 g before a reaction. After, there was 50 g of liquid and the rest was gas. How much mass was gas? Explain how this relates to conservation of matter.
Gas mass = 160 − 50 = 110 g.
Name two property changes caused by heating or cooling (not chemical changes).
expansion/contraction, change of state (ice melting), materials expanding when heated
Describe an everyday object that uses an insulator for safety and explain why the insulator is needed
Answers may vary.