Scientific Principles #1
The faster the molecules move, the __________________________ the temperature.
HIGHER
When a substance is heated, the molecules that make up the substance move __________________________.
Faster
All matter has ___________ and __________.
Mass and volume
Why do substances have different odors?
Odor is a property of a substance. They have different odors when they are made of different molecules. Molecules differ when they are made of a different type of atom, different numbers of atoms or different arrangement of atoms.
What is a change from solid to liquid called?
Melting
Temperature is a measurement of the average __________________________ of molecules.
Speed
In a solid, molecules stay in place and can only __________________________.
Vibrate
Water is in the solid phase as ice. It is heated and changes phase to liquid water. How did the water molecules change? Did they change size? Speed?
They are the same size and shape, but moving faster.
What are two detectors you could use to prove odors are in the air?
Carbon monoxide detector- carbon monoxide
Smoke detector- smoke
Nose- detects odor particles
Indicator paper- detected the ammonia particles
What is a change from liquid to solid called?
Freezing
As temperature increases, the volume of gas __________________________ . As temperature decreases, the volume of gas __________________________.
Increases, Decreases
__________________________ is when a substance changes from a solid state into a liquid state. The opposite process is called __________________________.
Melting, Freezing
A pot of water is placed on a hot stove. Small bubbles begin to appear at the bottom of the pot. The bubbles rise to the surface of the water and seem to pop or disappear. What are the bubbles made of?
Gaseous water or water vapor
A balloon is placed into cold liquid nitrogen. What will happen to the volume and why?
The volume will decrease because the molecules slow down and move closer together which decreases the pressure.
What is a change from liquid to gas called?
Evaporation or Boiling
__________________________ occurs when molecules at the surface of a liquid gain enough energy to enter the gaseous state.
Evaporation
Substances can change from a solid state to a gaseous state, and this is called __________________________.
Sublimation
The pot of water on the hot stove begins to boil rapidly. A glass lid is placed on the pot and water droplets begin forming on the inside of the lid. What word best describes what happened?
Condensation-
Water vapor changed back into a liquid when it hit the cool lid.
A balloon is heated back to room temperature, what happens to its volume?
What is a change from gas to liquid called?
Condensation
__________________________ occurs when water vapor in the air slows down sufficiently to become a liquid.
Condensation
What did we observe to help us understand sublimation?
Dry Ice
What happens to the water molecules when water at 24 degrees Celsius is cooled to 0 degrees Celsius and freezes?
It freezes- the molecules move slower and get closer together.
How would particles move in a gaseous state in a HOT room?
They would move quickly. They would be spread out. They would spread out to take the shape of the whole room and fill the space.
What is a change from solid to gas (without becoming a liquid first) called?
Sublimation