Changes in Matter
This type of change happens when ice melts into water.
Physical Change
A horizontal line on a distance-time graph shows this.
Sound is produced when an object does this.
vibrate
The part of the ear that vibrates first when sound enters.
eardrum
Joey dropped his sandwich and blamed “magnetism.” What force is really pulling it to the floor?
gravity
A reaction where new substances are formed.
Chemical Change
The formula to calculate average speed.
distance / time
The unit for measuring loudness.
decibel (db)
Astronauts need these to talk in space.
radios
Kimi screamed, “My atoms are shaking!” during a cold shower. What kind of energy is he really feeling less of?
heat energy
This is why a straw appears bent when placed in water.
refraction
If a car travels 150m in 30 seconds, its average speed is this.
5 m/s
This wave behavior causes an echo.
reflection
These particles move when sound travels through air.
What are air particles?
Michelle says her voice sounds weird in the bathroom because of “ghosts.” What scientific reason explains the echo?
sound reflection / echo
This type of change happens when paper is burnt.
Chemical change
A straight diagonal line going up shows this.
constant speed
If the frequency of a wave increases, this happens to the pitch.
becomes higher
This part of the ear helps turn vibrations into signals to the brain.
What is the cochlea? (or inner ear)
Jeff ran so fast in P.E. that he called himself “light speed Jeff.” Realistically, what measurement would the teacher use to prove how fast he ran?
speed or distance/time
This is the key difference between a chemical and physical change.
chemical change creates a new substance, but a physical change does not
This is what a steeper line on the graph tells us.
faster speed
Sound cannot travel in this environment.
vacuum (like space)
Without this, sound cannot travel.
What is a medium (solid, liquid, gas)?
Charles made a helmet to trap smells but forgot air needs to move. What’s the process called when gas spreads out?
diffusion