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Chemistry Review of Isotopes and Radioactivity 150 150 Deborah

Chemistry Review of Isotopes and Radioactivity

Overview Most elements have isotopes, but not all isotopes are radioactive. Many isotopes are stable variations in mass, occurring naturally.  Unstable isotopes decay into other isotopes and elements, and emit energy which is picked up as radioactivity. Isotopes An element is defined by the number of protons it has in its atomic nucleus.  For example,…

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Chemistry Review of Equilibrium 150 150 Deborah

Chemistry Review of Equilibrium

Overview: Chemical equilibrium refers to the state in which opposite processes balance each other so that one does not occur more than the other.  Many chemical processes exist which are reversible.  Equilibrium does not mean that reactions come to a stop, but that they balance dynamically. Reversible Reactions Reversible reactions are chemical processes that oppose…

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Chemistry Review of Types of Physical and Chemical Changes 150 150 Deborah

Chemistry Review of Types of Physical and Chemical Changes

Overview: Matter can undergo many types of changes.  Physical changes to a substance do not change its chemical composition, while chemical changes to a substance change its chemical composition.  Compare the difference between chopping wood, which breaks it into pieces and changes its physical composition, with burning wood, which changes its chemical composition. Changes in…

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Math Review of Relative Frequency 150 150 Deborah

Math Review of Relative Frequency

Overview: Relative frequencies refer to estimates of probabilities taken from actual data.  Suppose that a survey of 1000 voters is taken and 213 of them state that they are going to vote in favor of a certain issue.  The relative frequency would be 213/1000 or .213. Difference between Probability and Relative Frequency Suppose that a…

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Math Review of Probability without Counting 150 150 Deborah

Math Review of Probability without Counting

Overview Usually, probability is calculated in terms of relative numerical frequencies. However, it can also be calculated in terms of ratios of area. Probability of Area Suppose that a target is located on a board. A dart thrown at the board will land somewhere on the board, either outside the target or inside the target.…

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Math Review of Systems of Inequalities 150 150 Deborah

Math Review of Systems of Inequalities

Overview Systems of inequalities can be solved in much the same way as linear equations. If there is a solution in which the systems intersect, it will be in terms of a plane figure rather than a single point. Review of Inequalities Suppose the inequality is in the form x +y >2. The solution set…

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Math Review of Absolute Value Functions 150 150 Deborah

Math Review of Absolute Value Functions

Overview Absolute value functions are functions in which f(x) = │x│. They are important in a number of settings, including the study of error and probability functions. Definition of Absolute Value Absolute value is a measure of the distance of a number from 0. For any real number x, both x and –x have the…

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Math Review of Intersection and Union of Sets 150 150 Deborah

Math Review of Intersection and Union of Sets

Overview The intersection of sets refers to the elements that both sets have in common, while the union of sets refers to the elements that both sets have together.  If the sets are finite, the elements of the new set can be listed.  Otherwise, they can be described graphically, algebraically, or by the rule that…

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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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