Chemistry – Ch 1 – Flashcards
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__ is anyting that has mass and takes up space
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matter
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__ is the study of the properties of matter and how matter changes
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Chemistry
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A(n) __ is a substance that can't be broken down into any other substances by chemical or physical means
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element
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All of the matter around you is composed of ______
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one element or a combination of two or more elements
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A(n) __ is a substance made of two or more elements chemically combined in a specific ratio or proportion
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compound
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A(n) __ consists of two or more pure substances (elements, compounds, or both) that are in the same place but not chemically combined
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mixture
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A __ is a well-mixed mixture
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solution
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What is NaCl?
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table salt
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A __ is a change that alters the form or appearance of a material but doesn't convert the material into a new substance
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physical change
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A __ is a change in matter that forms one or more new substances.
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chemcial change
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A solid that forms and settles out of a solution (liquid mixture)
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precipitate
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The key characteristic of a chemical reaction is the production of new materials that are _____ from the starting materials
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chemically different
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A __ is a particle made of two or more atoms bonded together
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molecule
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A(n) __ is the smallest particle of an element
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atom
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Chemical reactions occur when ____ or _____
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chemical bonds break OR new bonds form
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What type of change? Baking a cake
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chemical
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What type of change? Burning a log
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chemical
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What type of change? Freezing water
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physical
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The smallest particle of an element is an __
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atom
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A __ has different properties than the elements that compose it and is made of substances combined in a specific ratio
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compound
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Salt water is a type of well-mixed mixture called a __
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solution
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A chemical change is also referred to as a _____
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chemical reaction
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A __ is a solid formed from a solution during a chemical reaction
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precipitate
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When combined substances retain their individual properties, the result is a __
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mixture
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A __ is formed or broken apart during a chemical reaction
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bond
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The combination of two or more atoms is called a __
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molecule
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An __ is the simplest type of substance and cannot be broken down into any other substances
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element
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__ is the study of the properties of matter and how matter changes
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chemistry
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__ is a process used to separate mixtures. You pour the mixture into a filter to separate it
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filtration
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Mixtures of liquids and heavy solids can be separated by __. You just need to give the solid time to settle to the bottom and then pour the liquid off the top
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decanting
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Another way to separate some mixtures is through the process of __
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evaporation
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A ___ is a shorter easier way to show chemical reactions, using symbols instead of words
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chemical equation
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___express a concept in a shorter form
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symbols
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A __ is a combination of symbols that represent the elements in a compound
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chemical formula
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A number in a chemical formula that tells the number of atoms in a molecule or the ratio of elements in a compound
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subscripts
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A __ is a substance that enters into a chemical reaction
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reactant
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A __ is a substance formed as a result of a chemical reaction
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product
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A chemical __ uses symbols and formulas to show the reactants and the products of a chemical reaction
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equation
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The amount of matter in a chemical reaction doesn't change. Therefore, the total mass of the reactants must __ the total mass of the products
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equal
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This principle staes that during a chemical reaction, matter is not created or destroyed
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conservation of mass
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The number in front of a chemical formula in an equation that indicates how many molecules or atoms each reactant and product are involved
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coefficient
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Chemical reactions can be classified in one of three categories:
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synthesis, decomposition, replacement
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A chemical reaction in which two or more simple substances combine to form a new more complex substance
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synthesis
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A chemical reaction that breaks down compounds into simpler products
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decomposition
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A chemical reaction in which one element replaces another in a compound, or when two elements in different compounds trade places
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replacement
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__ uses symbols and formulas to show chemical reactions
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chemical equation
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__ is a combination of symbols that represents the elements in a compound
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chemical formula
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__ is a reaction where comounds are broken down into simpler products
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decomposition
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__ are numbers telling how many molecules are involved in a chemical reaction
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coefficients
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__ are materials present after a reaction
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products
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__ are materials present before a reaction
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reactants
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__ states that matter is not created or destroyed during a chemical reaction
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conservation of mass
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__ is a reaction where substances combine to form a more complex compound
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synthesis
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__ is a reaction where one element replaces another in a compound
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replacement
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__ indicates how many atoms of an element are in one molecule
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subscript
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Every chemical reaction involves a change of ___
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energy
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Some chemical reactions __ energy and others __ energy.
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release/ absorb
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___ reactions are reactions that absorb energy in the form of heat
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exothermic
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___ reactions are reactions that release energy in the form of heat
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endothermic
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__ is the minimum amount of energy needed to get a chemical reaction started
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activation energy
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The rate of a chemical reaction is affected by such factors as __, ___, ___, by using substances called catalysts and inhibitors.
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concentration, surface area, and temperature
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The rate of a chemical reaction is affected by such factors as concentration, surface area, and temperature and by using substances called ___ and ___.
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catalysts and inhibitors
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__ is the strength of a solution
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concentration
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a material that accelerates the rate of a chemical reaction by lowering the activation energy
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catalyst
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a biological catalyst that lowers the activation energy of a reaction in a cell
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enzyme
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a material that decreases the rate of a reaction
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inhibitor
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__ is a rapid reaction between oxygen and fuel that results in a fire
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combustion
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__ is a material that releases energy when it burns
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fuel
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Three things are necessary to start and maintain a fire -
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fuel, oxygen, and heat
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Water removes__ parts of the fire triangle
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2 - (covers the fuel so it can't come in contact with oxygen) (evaporation cools the heat)
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What are the two most common sources of home fires?
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small heaters and faulty electric wiring
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To stop fires, what should you remove?
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one of the parts of the fire triangle
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What is one of the most effective ways to stop a small fire?
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fire extinguisher
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What is the best form of fire safety?
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prevention
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Name a way you can stop a small stove fire safely.
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cover it with baking soda. The liquids int he food will react with baking soda to make carbon dioxide. This will take out the oxygen part of the triangle
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Name two fire safety tips you should practice in your kitchen
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Don't keep paper by your stove, have a fire extinguisher handy, don't put water on a grease fire
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Name some examples of fuels
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oil, coal, wood, gasoline, paper
