States of Matter
What is the state of matter in which particles keep a rigid and fixed shape?
solid
Which example shows a solid changing into a liquid?
a. droplets of water forming on a cold windowpane.
b. Steam coming off of boiling water.
c. Juice freezing on a cold day outside.
d. Butter being melted in a pan.
d. Butter being melted in a pan.
What is another term for Thermal Energy?
Heat Energy
Which of the following changes is a physical change?
a. Rust forming on a nail
b. Cutting a piece of paper
c. Milk turning sour
d. A fire burning
b. Cutting a piece of paper
The amount of matter in an object is its _________.
mass
On examine the particles of some matter, an observer recognizes that they are filling the volume of the shape they are in. What state of matter is the substance?
a gas
What are TWO observations that indicate a phase change has occurred?
a. a block of cheese is cut into pieces.
b. A block of ice shrinks and disappears.
c. A liquid changes color.
d. A gas gives off a strong smell.
e. Gas bubbles form in boiling water.
B and E
What does it mean that something is a Thermal Conductor?
It transfers heat easily
Which of the following is a Chemical Change (results in a new substance)?
a. Ice Melting into Water
b. salt dissolving into water.
c. Mixing eggs and milk for an omelette
d. Gas forming when vinegar mixes with baking soda.
d. Gas forming when vinegar mixes with baking soda.
A container weights 200 mg. an ice cube on the container weights 200mg. After melting into water, how much will the container and water weigh?
400mg
Draw a model of liquid particles
Should show particles with a fixed volume, but NOT a fixed shape
What explains the appearance of Steam?
a. Water has turned into a solid.
b. Heat caused the water to boil into a gas.
c. Water froze due to temperature loss.
d. Steam formed from air mixing with water.
b. Heat caused the water to boil into a gas.
What does it mean that something is a Thermal Insulator?
It stops or slows the transfer of heat significantly
A student mixes two substances and wants to know if a new substance was formed. What are two pieces of evidence that would support that a new substance was created?
Changing color
giving off a gas
emitting a new odor after mixing
creating light
What is the Law of Conservation of Mass?
While matter can change form, it cannot be made to disappear.
Describe all 3 states of matter on Earth.
Solid- particles have fixed shape and volume.
Liquid- particles have fixed volume but no fixed shape.
Gas- Particles have neither a fixed volume or a fixed shape.
Which Two changes involve NO phase change?
a. Butter melting in a hot pan.
b. water evaporating from a cup left in the sun.
c. water flowing down a slide.
d. gas escaping a balloon when it pops.
e. water freezing into ice.
C and D
Is it accurate to say that a Thermal Conductor creates heat? Why or Why Not?
NO, it is not accurate. Thermal conductors transfer heat really well, but they don't produce it themselves.
A student combines salt and water. Choose the statements that describe this change.
a. The salt dissolves but does not change into something new.
b. A gas forms, so a new substance was made.
c. This is a physical change because the salt can be recovered.
d. The salt changes into a completely new material.
A and C
-Water evaporating in a closed container and the mass staying the same.
-Condensation forms on the side of a cold glass, but the weight doesn't change.
-Measuring crayons before and after they are melted in a sealed container.
All 3 of these would demonstrate what?
Law of conservation of mass
What term refers to how fast or slow liquid particles "flow?"
viscosity
0 minutes: Chocolate is placed in a dish.
2 minutes: Chocolate begins to melt.
4 minutes: Mostly liquid with small solid chunks.
6 minutes: Entirely liquid chocolate
8 minutes: small bubbles forming
10 minutes: Liquid chocolate boiling steadily
Which two phase changes occurred in this experiment?
Melting (Fusion) and Evaporation
Is a thermos a thermal conductor, or insulator? Explain
It is an insulator because it prevents heat from transferring out or in.
A student mixes ingredients to form a batter. They then heat it in the oven. A solid, darker substance is formed. What does this experiment show?
A chemical changes occurred, creating a new substance
A student places a wet towel on a scale in a sealed system. Over time, the water evaporates into a gas, and the towel dries out. What will happen to the weight shown on the scale?
It will remain the same, since the gas cannot escape, and mass remains the same.