States of Matter
A substance has a definite volume but takes the shape of its container. What state is it AND how are the particles arranged?
Liquid; particles are close together but move/slide past each other
A mixture looks uniform but can be separated physically. What is it AND why?
Homogeneous mixture; evenly mixed but not chemically combined
An element is shiny, conducts electricity, and is malleable. Classify it and justify.
Metal; those are metal properties
A substance changes shape but remains the same substance. What type of change?
Physical
A force causes an object to slow down over time. Identify the force.
Friction;
Why does a gas fill the entire container it is placed in?
Particles are far apart and move freely in all directions
A student mixes sand and salt. How could they separate them?
Dissolve salt in water (homogeneous) → filter sand (heterogeneous)
An element is brittle, dull, and does not conduct electricity. What is it?
Nonmetal
A reaction produces bubbles AND temperature change. What does this indicate?
Chemical change (new substance formed)
A student pushes a box left, another pushes right, and it doesn’t move. Explain.
Balanced forces (equal and opposite)
Compare kinetic energy in solids, liquids, and gases.
Solids = lowest, liquids = medium, gases = highest
Three liquids layer: honey (bottom), water (middle), oil (top). Rank density from greatest to least.
Honey > Water > Oil
Why are metalloids useful in electronics?
They are semiconductors (control flow of electricity)
Why is dissolving NOT a chemical change even though it “disappears”?
Substance is still there and can be recovered
Why does a ball roll farther on tile than carpet?
Less friction on tile
A student says “liquids have a definite shape.” Explain why this is incorrect.
Liquids do NOT have definite shape; they take the shape of their container
Why does an object float in one liquid but sink in another?
Its density is less than one liquid but greater than the other
A material conducts electricity but is brittle. Why might it NOT be a metal?
It could be a metalloid (semiconductor, brittle)
A student observes a precipitate forming. What does this prove?
A new substance formed → chemical change
A cart rolls down a ramp and hits an object. Explain what determines how far the object moves.
Applied force, friction, and surface type
How would increasing temperature affect particle motion in all states of matter?
Particles move faster → kinetic energy increases
A student claims “all mixtures can be separated easily.” Explain why this is incorrect.
Some mixtures require multiple steps or special processes these are homogeneous mixtures (filtration, evaporation, distillation)
A company needs a material for wiring that can bend without breaking AND conduct electricity. What properties AND classification are required?
Ductility + conductivity → metal
Compare burning wood vs melting ice (type of change + reasoning).
Burning = chemical (new substance), melting = physical (same substance)
What force is shown when a magnet moves a paperclip?
Magnetism