Matter/Chemical Change - Section 1 Flashcards
What is chemistry?
The science concerned with matter, the properties of matter, and the changes in matter
What is matter?
Anything that takes up space and has mass
What is a chemical?
Any substance used or produced in a chemical process
All natural materials are produced by chemical processes
What is a physical property?
A property that describes the appearance and composition of a substance
What are some examples of physical properties? (9)
Melting point Boiling point Hardness Malleability Ductility Crystal shape Solubility Density Conductivity
What is a chemical property?
A property that describes how a substance interacts chemically with other substances
What are some examples of chemical properties? (5)
Reaction with acids Reaction with water Ability to burn Behaviour in air Reaction to heat
What is melting?
Occurs when a solid changes to a liquid
What is evaporation?
A change from a liquid to a gas
What is condensation?
Is the change from a gas to a liquid
What is freezing?
A change from a liquid to a solid
What is sublimation?
Occurs if a solid goes directly to a gas
What is deposition?
Happens when a gas change directly to a solid
What are mixtures?
Are composed of two or more different substances whose proportions or ratios may vary
What are mechanical mixtures?
Is a type of mixture where you can see the different parts of the mixture
What is a solution?
Is a type of mixture where you only see one part
It appears to be one substance
What is a suspension?
Is a cloudy mixture in which tiny particles of one substance are held within another substance and could be separated by filtering
What is colloid?
Is a cloudy mixture but the suspended particles are so small that they cannot be separated out of the other substance
What are pure substances?
They have definite properties that are always the same
What are elements?
Pure substances that cannot be broken down into a simpler substances
They are composed of one type of atom
What are compounds?
Are pure substances that contain two or more elements in definite proportions
Can only be broken down through chemical reactions
What is a physical change?
A change where no new substances are produced
The material may change from state to state or its appearance may be altered in some way
What is a chemical change?
A change where one or more new substances are formed with different properties than the starting materials
What are some examples of evidence of a chemical change?
Change in colour Change in odour Heat or light is absorbed or given off A gas is formed A solid called a precipitate is formed Change is difficult to reverse
What are some examples of a physical change?
Boiling a solution
Salt dissolving in water
What are some examples of a chemical change?
Vinegar and baking soda
Fireworks
