Calculating Half-Life - Chemistry LibreTexts
What is the difference between absolute dating and relative dating? 2. What are the Answer the rest of the questions on this worksheet on your own. You may. Understanding Geologic Time introduces students to geologic time, the evidence for events in Earth's history, relative and absolute dating techniques, and the. Fossils and Relative Dating Worksheet. _____ 1. Using the diagram below, which of the following. fossils (A, B or C) is the oldest? How do you know? _____ 2.
A mobilization strategy aimed at large-scale change often begins with action a small issue that concerns many people. Popovic also argues that a social movement has little chance of growing if it relies on boring speeches and the usual placard waving marches.
He argues for creating movements that people actually want to join. It turned fatalism and passivity into action by making it easy, even cool, to become a revolutionary; branding itself within hip slogans, rock music and street theatre. Tina Rosenbergin Join the Club, How Peer Pressure can Transform the World,  shows how movements grow when there is a core of enthusiastic players who encourage others to join them.
Types of social movement[ edit ] Types of social movements. Examples of such a movement would include a trade union with a goal of increasing workers rightsa green movement advocating a set of ecological laws, or a movement supporting introduction of a capital punishment or the right to abortion.
Some reform movements may aim for a change in custom and moral norms, such as condemnation of pornography or proliferation of some religion. The singularitarianism movement advocating deliberate action to effect and ensure the safety of the technological singularity is an example of an innovation movement.
- Social movement
For example, the anti-technology 19th century Luddites movement or the modern movement opposing the spread of the genetically modified food could be seen as conservative movements in that they aimed to fight specific technological changes. Some of these groups transform into or join a political partybut many remain outside the reformist party political system.
Most religious movements would fall under this category.
The American Civil Rights movement, Polish Solidarity movement or the nonviolentcivil disobedience -orientated wing of the Indian independence movement would fall into this category. Most of the oldest recognized movements, dating to late 18th and 19th centuries, fought for specific social groups, such as the working class, peasants, whites, aristocrats, Protestants, men.
They were usually centered around some materialistic goals like improving the standard of living or, for example, the political autonomy of the working class. Notable examples include the American civil rights movementsecond-wave feminismgay rights movementenvironmentalism and conservation effortsopposition to mass surveillanceetc. They are usually centered around issues that go beyond but are not separate from class.
5.7: Calculating Half-Life
Movements such as the first where Marx and Bakunin metsecondthird and fourth internationalsthe World Social Forumthe Peoples' Global Action and the anarchist movement seek to change society at a global level. Identification of supporters[ edit ] A difficulty for scholarship of movements is that for most of them, neither insiders to a movement nor outsiders apply consistent labels or even descriptive phrases.
Unless there is a single leader who does that, or a formal system of membership agreements, activists will typically use diverse labels and descriptive phrases that require scholars to discern when they are referring to the same or similar ideas, declare similar goals, adopt similar programs of action, and use similar methods.
There can be great differences in the way that is done, to recognize who is and who is not a member or an allied group: Often exaggerate the level of support by considering people supporters whose level of activity or support is weak, but also reject those that outsiders might consider supporters because they discredit the cause, or are even seen as adversaries.
Those not supporters who may tend to either underestimate or overestimate the level or support or activity of elements of a movement, by including or excluding those that insiders would exclude or include. It is often outsiders rather than insiders that apply the identifying labels for a movement, which the insiders then may or may not adopt and use to self-identify.
For example, the label for the levellers political movement in 17th-century England was applied to them by their antagonists, as a term of disparagement. Yet admirers of the movement and its aims later came to use the term, and it is the term by which they are known to history.
Caution must always be exercised in any discussion of amorphous phenomena such as movements to distinguish between the views of insiders and outsiders, supporters and antagonists, each of whom may have their own purposes and agendas in characterization or mischaracterization of it.
Dynamics of social movements[ edit ] Stages of social movements. They have a life cycle: They are more likely to evolve in the time and place which is friendly to the social movements: Social movements occur in liberal and authoritarian societies but in different forms. However, there must always be polarizing differences between groups of people: In case of the 'new movements', they are more likely to be the differences in customs, ethics and values.
Finally, the birth of a social movement needs what sociologist Neil Smelser calls an initiating event: For example, the Civil Rights Movement grew on the reaction to black woman, Rosa Parksriding in the whites-only section of the bus although she was not acting alone or spontaneously—typically activist leaders lay the groundwork behind the scenes of interventions designed to spark a movement.
The Polish Solidarity movement, which eventually toppled the communist regimes of Eastern Europedeveloped after trade union activist Anna Walentynowicz was fired from work. The South African shack dwellers' movement Abahlali baseMjondolo grew out of a road blockade in response to the sudden selling off of a small piece of land promised for housing to a developer. Such an event is also described as a volcanic model — a social movement is often created after a large number of people realize that there are others sharing the same value and desire for a particular social change.
One of the main difficulties facing the emerging social movement is spreading the very knowledge that it exists.
Explorations Through Time
Second is overcoming the free rider problem — convincing people to join it, instead of following the mentality 'why should I trouble myself when others can do it and I can just reap the benefits after their hard work'. To calculate the age of a substance using isotopic dating, use the equation below: Ra has a half-life of years. Radioactive Dating Using Nuclides Other than Carbon Radioactive dating can also use other radioactive nuclides with longer half-lives to date older events.
For example, uranium which decays in a series of steps into lead can be used for establishing the age of rocks and the approximate age of the oldest rocks on earth.
Late Middle Ages
Since U has a half-life of 4. In a sample of rock that does not contain appreciable amounts of Pb, the most abundant isotope of lead, we can assume that lead was not present when the rock was formed. Therefore, by measuring and analyzing the ratio of U Pb, we can determine the age of the rock.
This assumes that all of the lead present came from the decay of uranium If there is additional lead present, which is indicated by the presence of other lead isotopes in the sample, it is necessary to make an adjustment. Potassium-argon dating uses a similar method.
K decays by positron emission and electron capture to form Ar with a half-life of 1. If a rock sample is crushed and the amount of Ar gas that escapes is measured, determination of the Ar K ratio yields the age of the rock. Other methods, such as rubidium-strontium dating Rb decays into Sr with a half-life of As ofthe oldest known rocks on earth are the Jack Hills zircons from Australia, found by uranium-lead dating to be almost 4.
An ingenious application of half-life studies established a new science of determining ages of materials by half-life calculations. After one half-life, a 1. Present day estimates for the age of the Earth's crust from this method is at 4 billion years. Isotopes with shorter half-lives are used to date more recent samples. Chemists and geologists use tritium dating to determine the age of water ocean and fresh. In addition, tritium dating can be useful in determining the age of wines and brandies.
Summary and Vocabulary The half-life of an isotope is used to describe the rate at which the isotope will decay and give off radiation. Using the half-life, it is possible to predict the amount of radioactive material that will remain after a given amount of time.
Its half-life is approximately years. Radiation that comes from environment sources including the earth's crust, the atmosphere, cosmic rays, and radioisotopes.
These natural sources of radiation account for the largest amount of radiation received by most people. The half-life of a radioactive substance is the time interval required for a quantity of material to decay to half its original value.