Physical vs Chemical Changes, Phase Changes, DCA 3 8th Grade Science
liquid
A state of matter that has no definite shape but has a definite volume.
open system
A system in which matter can enter from or escape to the surroundings.
closed system
A system in which no matter is allowed to enter or leave
Physical Change
Absorbing water
gas
A state of matter with no definite shape or volume
o degress C
At what temperature does the solid start melting?
Chemical Change
Burning Wood
Chemical Change
Burning toast
Chemical Change
Cooking
solid
Definite shape and volume
Physical Change
Deflating an object
evaporating
Jean has a sample of a liquid. If she changes the liquid's phase by ___________________ it, the molecules will spread out, allowing the sample to expand and fill a container of any shape or volume.
Chemical Change
Light Production
Physical Change
Mixing Kool Aid
Chemical Change
Molding
evaporation
The change of a substance from a liquid to a gas
phase change
a transition of matter from one state to another
deposition
gas to solid
cooled metal
will contract (molecules will get closer together)
heated metal
will expand (molecules will spread out)
physical change
A change in a substance that does not change its identity
chemical change
A change that occurs when one or more substances change into entirely new substances with different properties.
Chemical Change
Change of color from reaction
Physical Change
Condensing
at 120°C
Consider the temperature versus time graph below. At what temperature is the boiling point of this substance? at 0°C
Physical Change
Cutting fruit
Chemical Change
Digesting
Physical Change
Hammering nails into a board
sublimation
In which phase transition do molecules directly move from a state involving vibration of particles in a fixed position to a state involving random movement of high-speed particles?
2
In which region is the substance in both the solid phase and the liquid phase?
Physical Change
Melting
Physical Change
Mixing ingredients with no reaction
Chemical Change
Oxidizing
condensation
The change from a gas to a liquid
melting
The change in state from a solid to a liquid
freezing
The change of state from a liquid to a solid
5
The diagram below shows the different phase transitions that occur in matter. Which arrow would most likely represent the phase change that occurs when silver is poured into a mold and cools to become a solid bar?
during sublimation
When does carbon dioxide absorb the most heat energy?
Heat energy is released by the substance.
Which best describes the energy change that takes place during deposition?
Heat energy is absorbed by the substance.
Which energy change occurs during boiling?
Molecules are speeding up as boiling occurs.
Which statement best describes the process that arrow 1 represents?
Physical Change
cutting hair
Chemical Change
melting snow
phase diagram
shows the states of matter and phase changes at certain temperatures
sublimation
solid to gas
Physical Change
A change in a substance that does not involve a change in the identity of the substance
Chemical Change
A change in matter that produces one or more new substances
Physical Properties
A characteristic of a pure substance that can be observed without changing it into another substance
A substance that has a specific shape and volume changes to a substance that has a specific volume.
A solid substance turns into a liquid. Which best describes this change?
Chemical Change
Bleaching hair
Physical Change
Boiling
Physical Change
Breaking
It is true because heat is released when a gas changes to a liquid.
Consider the statement below. "When nitrogen is liquefied, heat is released." Is this statement true or false?
Physical Change
Cooling Lava
Physical Change
Cracking
Physical Change
Crumpling
Chemical Change
Eroding
Physical Change
Evaporating
Chemical Change
Exploding (Combustion)
Chemical Change
Formation of gas/bubbles
Physical Change
Freezing
Physical Change
Freezing ice
Chemical Change
Frying
Chemical Change
Glowing
Chemical Change
Photosynthesis
Chemical Change
Producing Heat
Chemical Change
Producing a smell from glands
Chemical Change
Reacting to mixture
Physical Change
Ripping/Tearing
Chemical Change
Roasting
Chemical Change
Rotting (Fermenting)
Chemical Change
Rusting
Physical Change
Subliming
Chemical Change
Tablets fizzing
Chemical Change
Tarnishing
1, 2, and 3
The arrows in the chart below represent phase transitions. Which arrows represent the phase transitions in which heat energy is gained? 1, 2, and 3 2, 3, and 5 3, 4, and 5 4, 5, and 6
from a gas to a liquid
Water is initially present in a state where its molecules are far apart. During a change of state, its molecules slow down. Which change of state has most likely taken place?
4
Which arrow would most likely represent the phase change that involves the same amount of energy as arrow 1?
freezing ice cream
Which example involves a phase change in which heat energy is released by the substance?freezing ice cream cooking a pot of soup melting ice under sunlight watching frost disappear into air
chemical property
a property of matter that describes a substance's ability to react with something
physical property
a quality or condition of a substance that can be observed or measured without changing the substance's composition
Chemical Change
shooting fire crackers