Physical and Chemical Change Flashcards
What is physical change?
physical change is being a change in which no new substance is formed.
What is melting?
Melting ice is known as a physical change as it only involves a change in the physical state of water, from ice to water in the liquid state.
What is freezing?
Freezing of water is a physical change because only the physical state of water is changed; i.e. water is converted into ice.
What is evaporation?
The process of change of state from liquid to a gas is called evaporation. It is a physical change as no new substance is formed. When water evaporates, it changes from liquid state to gas state, but it is still the same water H2O chemically.
what is condensation?
Condensation is a physical change. In condensation, a gas turns into a liquid. The molecules of the gas do not change when they turn into the liquid, indicating it is just a physical change.
Examples of changing shape
Bending, cutting, twisting.
What is expansion?
Inlarging or making bigger
What are some examples of expansion?
Water has the unusual property in that it also expands when it freezes. This makes ice float.
Thermal expansion can be anything that is heated so it expands or the opposite cooled so it expands.
Metal expands in the heat.
What is contraction?
Thermal contraction, or shrinking of materials, occurs when materials are subjected to a decrease in temperature. It occurs in all types of matter, whether it is solid, liquid, or gas.
What are some examples of contraction?
1) snapping of taut power lines during winter; (2) deflation of balloon when placed in ice-cold water; and (3) breakage of an initially hot glass placed under cold running water.
What is changing states?
When the matter changes from one state to another.
What are some examples of changing states?
Evaporation, melting, freezing, condensation
What is mixing?
In chemistry, when two or more substances mix with each other without participating in a chemical change, the resulting substance is called a Mixture. The result formed due to the combination of substances does not lose its individuality nor are they combined chemically.
What are some examples of mixing?
Examples include blood, milk, salt and water, sand and water
What are some ways to detect the presence of a new substance?
Chemical reactions are also known as chemical changes. There are many different ways to spot a chemical change. Five different signs include odor, temperature change, precipitate formation, production of gas bubbles, and a color change.