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Science.2 Phase Changes & Matter (Chapter 3 & 4)
Phase changes, matter, mixtures, compounds, elements
48
Science
8th Grade
12/08/2010

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Cards

Term
What are the four classes of matter?
Definition
Mixtures, solutions, elements and compounds
Term
What is matter that consists of two or more substances mixed together but not chemically combined?
Definition
Mixture
Term
What are three properties of mixture?
Definition
1. substances in mixture keep their properties
2. can see different particles and can be separated
3 not chemically combined
Term
What are some examples of a mixture?
Definition
cereal, sugar-water, concrete, granite
Term
How are mixtures classified?
Definition
The are classified on how well they are mixed.
Term
Define heterogeneous mixture. Give example.
Definition
A mixture that does not appear to be the same throughout.
Example: Concrete or Oil & vinegar
Term
What are some properties of heterogeneous mixtures?
Definition
particles are large enough to be seen, can be separated
Term
Define homogeneous mixture. Give examples.
Definition
A mixture that appears to be the same throughout.
Example: milk, toothpaste, steel, whipped cream
Term
What are two properties of homogeneous mixtures?
Definition
1. particles are very small not easily recognizable
2. particles do not settle when mixture is allowed to stand
Term
Define element.
Definition
simplest pure substance cannot be broken into something simpler
Term
What is the smallest particle of an element that has the properties of that element?
Definition
atom
Term
What are Chemical Symbols?
Definition
a shorthand way of representing the element
Term
Define a compound.
Definition
pure substances that are made of more than one element, (2 or more) elements that are chemically combined
Term
Give examples of a compound.
Definition
Baking Soda, carbon dioxide, sugar, TNT
Term
How are compounds different than elements?
Definition
Compounds can be broken down into simpler substances.
Term
Properties of the elements that make up a compound are often quite ________________ from the properties of the compound.
Definition
different
Term
What is a molecule?
Definition
it is made up of 2 or more atoms chemically bonded together. It is the smallest particle of a compound that has all the properties of a compound
Term
Give example of compound.
Definition
Water, steel
Term
What are some general properties of matter?
Definition
mass, volume, weight density
Term
A _______________ property is when the characteristics of a substance can be observed without changing the identity of a substance.
Definition
physical
Term
What are the different phases of matter?
Definition
solid, liquid, gas
Term
What phase of matter has a definite shape and definite volume?
Definition
solid
Term
Why do solids have a definite shape?
Definition
A solid has particles that are closely packed together, because of the arrangement they cannot move far or out of place or flow over or around each other.
Term
What phase of matter has particles that are close together, free to move about, has no definite shape but has a definite volume?
Definition
Liquid
Term
What phase of matter does not have a definite shape or a definite volume, fills all available space in a container, regardless of the size or shape of the container.
Definition
Gas
Term
What are the 3 phases of matter?
Definition
solid, liquid, gas
Term
What are the 3 different phases of water?
Definition
Ice, liquid, water vapor
Term
What causes the particles of a substance to be in one particular phase rather than another?
Definition
energy
Term
What can be said about the energy found in a gas compared to that of a liquid?
Definition
more energy in a gas
Term
By adding more energy to a substance, what does it do to the particles of that substance?
Definition
Causes the particles to move faster and farther apart
Term
What has to happen for ice to change to liquid water?
Definition
add energy
Term
What has to happen for water vapor to change to a liquid?
Definition
lose energy
Term
A ______________ is when a substance changes from one form to another, but it remains the same kind of substance.
Definition
Physical change
Term
What is the definition of melting?
Definition
A change from a solid to a liquid.
Term
Melting occurs when a substance _______________.
Definition
absorbs heat energy
Term
What is the temperature at which a solid changes to a liquid called?
Definition
melting point
Term
What is the definition of freezing?
Definition
phase change of a liquid changing to a solid
Term
Freezing occurs when a substance ____________________.
Definition
loses heat energy
Term
What is the temperature at which a liquid changes to a solid called?
Definition
freezing point
Term
What is it called when a substance changes from a liquid to a gas?
Definition
vaporization
Term
What has to happen to the heat energy for vaporization to occur?
Definition
absorb heat energy
Term
What is it the temperature called at which a liquid turns to a gas?
Definition
boiling point
Term
Explain the difference between evaporation and boiling.
Definition
Evaporation comes from the surface of the liquid and boiling is from within the liquid.
Term
Define condensation.
Definition
gas changes to a liquid
Term
What has to happen to the heat energy for condensation to occur?
Definition
lose heat energy
Term
Other than the examples of color, shape, hardness, and texture used to describe physical properties, what other examples?
Definition
melting/freezing point and boiling point
Term
A _______________ property is when a substance changes into another new substance.
Definition
chemical
Term
Changes that substances undergo when they turn into other substances is called ________________________.
Definition
chemical changes
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