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Chemistry Review of Triboluminescence 150 150 Deborah

Chemistry Review of Triboluminescence

Overview Some materials give off sparks of light when they are rubbed, crushed, or broken.  This phenomenon is known as triboluminescence or fractoluminescence.  It may hold clues to how changes in pressure produce chemical reactions. Quartz and Sugar Crystals Quartz is a mineral that forms very large crystals.  Centuries ago, it was used in ceremonies…

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Chemistry Overiew of Solutions 150 150 Deborah

Chemistry Overiew of Solutions

Overview Many common substances exist as solutions, such as the air we breathe, the water that surrounds us, and brass instruments. Solutions are mixtures of two or more substances that are combined so thoroughly that it is difficult to separate the parts. Definition Solutions consist of a solute (the substance that is dissolved) and the…

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Chemistry Review of Heat in Reactions 150 150 Deborah

Chemistry Review of Heat in Reactions

Overview Many chemical reactions involve heat energy. They either release energy in the form of heat, or absorb energy in the form of heat from the environment. Exothermic and Endothermic Reactions Exothermic reactions generate heat. For example, liquid propane in a camp stove burns oxygen from the air to release heat in a chemical reaction…

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Chemistry Review of Molecular Shape and Polarity 150 150 Deborah

Chemistry Review of Molecular Shape and Polarity

Overview Symmetrical molecules tend to follow basic structural shapes, such as linear, planar, tetrahedral, pyramidal, and bent. Some molecules also exhibit polarity, which gives them a distinct positive or negative charge. VSEPR Theory The shape of many small molecules can be predicted by the valence-shell electron pair repulsion theory or VSEPR for short. Electron pairs…

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Chemistry Review of Rates of Reactions 150 150 Deborah

Chemistry Review of Rates of Reactions

Overview Reaction rates in chemistry are based on how fast that reactants turn into products. Some of the elements that affect reaction rates include the nature of the chemicals that act as reactants, the number and strength of the chemical bonds to be broken and formed, temperature, and the presence of catalysts. Chemical Kinetics Suppose…

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Math Review of Weighted Averages and Mixtures 150 150 Deborah

Math Review of Weighted Averages and Mixtures

Overview: Calculating the values for weighted averages and mixtures is common to many fields, from education to chemistry.  The calculations for both require attention to the amount of each quantity and its relationship to the whole. Weighted Averages: Suppose a student takes 6 math tests with an average of 87.  The final is worth 2…

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Math Overview of the Distributive Propery 150 150 Deborah

Math Overview of the Distributive Propery

Overview: The Distributive Property in math can be used to solve equations by combining like terms.  It is another tool to simplify complicated problems by using common patterns of multiplication over addition or subtraction. Definitions: Figure 1:  Formal definition of the Distributive Property In arithmetic, the distributive property was defined with examples such as 4(3…

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Math Review of Factorials 150 150 Deborah

Math Review of Factorials

Overview: Factorials involve all possible outcomes of an event.  They are calculated by multiplying the number of possible events times the number of events minus 1 times the number of events minus 2 until there is only one possibility left. Figure 1:  The factorial formula in mathematical symbols Example of a Factorial: Suppose four actresses…

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Math Review of Functions 150 150 Deborah

Math Review of Functions

Overview: In a mathematical function, each value of x (the domain) can be matched with only one value of y (the range).  If there is one value for x, but multiple values of y, the relationship is not a function, but a relation.  Many different types of functions can be described by plotting the values…

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Math Review of Using Quadratic Equations 150 150 Deborah

Math Review of Using Quadratic Equations

Overview: Solving quadratic equations is an important skill in algebra.  Some methods of solving quadratic equations include factoring, taking the square root of both sides, completing the square, and using the quadratic formula.  There are many applications where quadratic equations can be used, such as motion, time, distance, and speed. What Is a Quadratic Equation?…

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