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Half-Life

Students review results from nuclear decay experiments and learn how the law of the conservation of matter applies to nuclear chemistry. Students also learn what a half-life is, how it can be used to determine the age of a fossil, and how to solve a half-life problem.

Students review results from nuclear decay experiments and learn how the law of the conservation of matter applies to nuclear chemistry. Students also learn what a half-life is, how it can be used to determine the age of a fossil, and how to solve a half-life problem.

Premiere Date: August 16, 2016 | Runtime: 00:22:59

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Toolkit

Half-Life Lab
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Unit 11C Note Taking Guide & Segment Questions
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Crosscutting Concepts

Patterns

Observed patterns of forms and events guide organization and classification, and they prompt questions about relationships and the factors that influence them.

Energy and Matter

Flows, cycles, and conservation. Tracking fluxes of energy and matter into, out of, and within systems helps one understand the systems’ possibilities and limitations.

Scale, Proportion, and Quantity

In considering phenomena, it is critical to recognize what is relevant at different measures of size, time, and energy and to recognize how changes in scale, proportion, or quantity affect a system’s structure or performance.

Stability and Change

For natural and built systems alike, conditions of stability and determinants of rates of change or evolution of a system are critical elements of study.

Science & Engineering Practices

Analyzing and Interpreting Data

Once collected, data must be presented in a form that can reveal any patterns and relationships and that allows results to be communicated to others. Because raw data as such have little meaning, a major practice of scientists is to organize and interpret data through tabulating, graphing, or statistical analysis. Such analysis can bring out the meaning of data—and their relevance—so that they may be used as evidence.
Engineers, too, make decisions based on evidence that a given design will work; they rarely rely on trial and error. Engineers often analyze a design by creating a model or prototype and collecting extensive data on how it performs, including under extreme conditions. Analysis of this kind of data not only informs design decisions and enables the prediction or assessment of performance but also helps define or clarify problems, determine economic feasibility, evaluate alternatives, and investigate failures. (NRC Framework, 2012, p. 61-62)

Using Mathematics and Computational Thinking

Although there are differences in how mathematics and computational thinking are applied in science and in engineering, mathematics often brings these two fields together by enabling engineers to apply the mathematical form of scientific theories and by enabling scientists to use powerful information technologies designed by engineers. Both kinds of professionals can thereby accomplish investigations and analyses and build complex models, which might otherwise be out of the question. (NRC Framework, 2012, p. 65)

Vocabulary

acid - substances that ionize in solutions to form H^+ ions. 

amphoteric - a substance that can be an acid or a base. 

Arrhenius Model - in aqueous solutions, acids form hydrogen ions (H^+).

base - substances that ionize in solutions and form OH^- ions. 

binary acids - acids that do not contain oxygen in their chemical formula. 

boiling point elevation - occurs when the boiling point of a solution is higher than the boiling point of the pure solvent alone. 

Bronsted-Lowry Model - this model states that any compound that can transfer a proton to any other compound is an acid, and the compound that accepts the proton is a base. 

colligative properties - properties of the solution that are different than those of a pure solvent by itself. 

dilution - the process of adding more solvent to a solution. 

electrolysis - the decomposition of water.

freezing point depression - a colligative property that describes how the freezing point of a solution is lowered compared to the freezing point of the pure solvent. 

heterogeneous mixture - a combination of two or more substances in which the original substances are separated into physically distinct regions with differing properties. 

homogeneous mixture - a combination of two or more substances that have uniform composition and chemical properties throughout; also known as a solution. 

insoluble - a solid, liquid, or gas that will not dissolve in a particular solvent.

Lewis Model - bases donate pairs of electrons and acids accept pairs of electrons.

mass percent - a way of expressing how concentrated a solution is; is equal to the mass of the solute in a solution divided by the total mass of the solution and multiplying by 100.

mixture - a combination of two or more pure substances in which each pure substance retains its individual chemical properties. 

molality - a ratio of moles of solute to the mass of the solvent in kilograms. 

molarity - a ratio of moles of solute to the volume of the solution in liters.

oxyacids - acids that contain oxygen in their chemical formula. 

pure substance - a material that has a constant composition and has consistent properties throughout the sample. 

saturated solution - a solution in which the maximum amount of solute has been dissolved in a given amount of solvent at a particular temperature. 

saturation point - the point at which no more solute can be dissolved in the solution at that particular temperature. 

solubility - the maximum amount of a substance that can be dissolved in a given quantity of solvent at a given temperature to produce a saturated solution. 

solute - the substance that is being dissolved in a solution. 

solution - a liquid mixture in which the solute is uniformly distributed within the solvent. 

solvent - the substance that is present in a greater amount in a solution. 

supersaturated solution - a solution that is holding more dissolved solute than what it normally would hold at that temperature.

Georgia Standards of Excellence

SC1Obtain, evaluate, and communicate information about the use of the modern atomic theory and periodic law to explain the characteristics of atoms and elements.

SPS4Obtain, evaluate, and communicate information to explain the changes in nuclear structure as a result of fission, fusion and radioactive decay.

SPS4.bUse mathematics and computational thinking to explain the process of half-life as it relates to radioactive decay. (Clarification statement: Limited to calculations that include whole half-lives.)

Request Teacher Toolkit

The Chemistry Matters teacher toolkit provides instructions and answer keys for labs, experiments, and assignments for all 12 units of study. GPB offers the teacher toolkit at no cost to Georgia educators. Complete and submit this form to request the teacher toolkit. You only need to submit this form one time to get materials for all 12 units of study.