Transition State Theory

Examples of Transition State Theory in the following topics:

• Transition State Theory

  • Transition state theory (TST) describes a hypothetical "transition state" that occurs in the space between the reactants and the products in a chemical reaction.
  • The species that is formed during the transition state is known as the activated complex.
  • According to transition state theory, between the state in which molecules exist as reactants and the state in which they exist as products, there is an intermediate state known as the transition state.
  • However, according to transition state theory, a successful collision will not necessarily lead to product formation, but only to the formation of the activated complex.
  • Transition state theory is most useful in the field of biochemistry, where it is often used to model reactions catalyzed by enzymes in the body.

• Physical Properties and Atomic Size

  • These can most easily occur when the metal is in a high oxidation state.
  • In each case the metals (Cr and Mn) have oxidation states of +6 or higher.
  • A metal-to ligand charge transfer (MLCT) transition will be most likely when the metal is in a low oxidation state and the ligand is easily reduced.
  • The pattern of splitting of the d orbitals can be calculated using crystal field theory.
  • Ferromagnetism is the physical theory which explains how materials become magnets.

• Coloring Agents

  • This approach is described by the ligand field theory (LFT) and the molecular orbital theory (MO).
  • Ligand field theory, introduced in 1935 and built from molecular orbital theory, can handle a broader range of complexes.
  • Metal complexes often have spectacular colors caused by electronic transitions due to the absorption of light.
  • Most transitions that are related to colored metal complexes are either d–d transitions or charge transfer bands.
  • Conceptually, one can imagine the oxidation state of the metal increasing by one (losing on electron), while the oxidation state of the ligand decreases by one (becomes anionic).

• Crystal Field Theory

  • Crystal field theory states that d or f orbital degeneracy can be broken by the electric field produced by ligands, stabilizing the complex.
  • The Crystal Field Theory (CFT) is a model for the bonding interaction between transition metals and ligands.
  • CFT successfully accounts for some magnetic properties, colors, and hydration energies of transition metal complexes, but it does not attempt to describe bonding.
  • the metal's oxidation state (a higher oxidation state leads to a larger splitting)
  • Crystal field stabilization is applicable to the transition-metal complexes of all geometries.

• Demographic Transition Theory

  • Demographic transition theory outlines five stages of change in birth and death rates to predict the growth of populations.
  • Demographic transition theory (Caldwell and Caldwell 2006) suggests that future population growth will develop along a predictable four- or five-stage model.
  • An example of this stage is the United States in the 1800s.
  • For countries with intermediate fertility rates (the United States, India, and Mexico all fall into this category), growth is expected to be about 26 percent.
  • Break down the demographic transition model/theory into five recognizable stages based on how countries reach industrialization

• Models of Urban Growth

  • This theory, known as the "broken windows theory," argues that small indicators of neglect, such as broken windows and unkempt lawns, promote a feeling that an area is in a state of decay.
  • Smart growth programs often incorporate transit-oriented development goals to encourage effective public transit systems and make bicyclers and pedestrians more comfortable.
  • As an approach to urban planning, it encompasses principles such as traditional neighborhood design and transit-oriented development.
  • A neighborhood designed along New Urbanist principles would have a discernible center (such as a square or a green) with a transit stop nearby.
  • Summarize the various theories of urban growth and the implications each theory has for today's society

• Relationship Between Expectations and Inflation

  • Anything that is nominal is a stated aspect.
  • This is the nominal, or stated, interest rate.
  • The theory of adaptive expectations states that individuals will form future expectations based on past events.
  • The theory of rational expectations states that individuals will form future expectations based on all available information, with the result that future predictions will be very close to the market equilibrium.
  • According to adaptive expectations theory, policies designed to lower unemployment will move the economy from point A through point B, a transition period when unemployment is temporarily lowered at the cost of higher inflation.

• Components of a Speech: Main Points, Introduction, Conclusion, and Transitions

  • A speech should have four components: the main points, introduction, conclusion, and transitions.
  • The introduction should get the audience's attention, describe the topic, state the thesis or purpose, and give an overview of the speech and its main points.
  • The conclusion should summarize main points and state a strong thesis.
  • A transition is a change or shift from one topic to another.
  • Speakers can emphasize transition points with visual aids, body language, vocal delivery, and transitional words and phrases.

• Population Trends

  • Most European nations are examples of countries at the end of the demographic transition: both birth and death rates are low, so populations are static or shrinking.
  • The demographic transition helps explain the differences between countries.
  • A new fear for many governments, particularly those in countries with very low fertility rates, is underpopulation—a state in which the declining population reduces the GDP and economic growth of the country, as population growth is often a driving force of economic expansion.
  • His arguments are widely known as Malthusianism, and present-day proponents of this theory are called Neo-Malthusians.
  • This model illustrates the demographic transition, as birth and death rates rise and fall but eventually reach equilibrium.

• Theoretical Perspectives on Childhood Socialization

  • One of the most widely applied theories of childhood is Jean Piaget's theory of cognitive development.
  • His approach to childhood development has been embraced by schools, and the pedagogy of preschools in the United States.
  • In 1979, psychologist Urie Bronfenbrenner published The Ecology of Human Development, setting forth his theory known as ecological systems theory.
  • The chronosystem refers to the patterning of environmental events and transitions over one's life course, as well as broader sociohistorical developments.
  • Contrast the various theories of childhood development, such as Freud's psychosexual theory, Piaget's stages of development and ecological systems theory