Chemistry Key Words and Definitions
10 Questions
1 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What does the term absorptivity represent in the context of light absorption?

  • The intensity of light transmitted through a solution
  • The measure of absorption at a concentration of 1 g/L (correct)
  • The total light scattered by particles in a solution
  • The amount of light emitted by a substance
  • In Beer's Law, which variable is inversely proportional to transmittance?

  • Wavelength
  • Concentration
  • Sample path length
  • Absorbance (correct)
  • What is primarily measured in flow cytometry?

  • Spectral band width of a light beam
  • Fluorescence emitted from aggregated cells
  • Physical or chemical characteristics of individual cells (correct)
  • Absorbance of a solution over time
  • How is molar absorptivity defined mathematically?

    <p>ε = A / (c * l)</p> Signup and view all the answers

    What phenomenon does chemiluminescence describe?

    <p>Emittance due to biochemical reactions</p> Signup and view all the answers

    Which aspect does a bandpass filter control?

    <p>Range of wavelengths transmitted</p> Signup and view all the answers

    What distinguishes atomic absorption spectrophotometry from other methods?

    <p>It atomizes the sample and measures absorbed radiation</p> Signup and view all the answers

    What basic principle do fluorometry and fluorescence depend on?

    <p>Molecule absorption and re-emission of light</p> Signup and view all the answers

    In nephelometry, what is primarily measured?

    <p>Scattered light from particles at angles to the incident light</p> Signup and view all the answers

    Which process is involved in bioluminescence?

    <p>Emission of light from an enzyme-enhanced biochemical reaction</p> Signup and view all the answers

    Study Notes

    Key Terms in Light Absorption and Spectrophotometry

    • Absorbance: Represents the light absorbed by a sample; mathematically expressed as log(1/T) or -log(T), where T indicates transmittance.

    • Absorptivity: A constant that quantifies light absorption at a specific wavelength, defined for a 1 g/L concentration of a compound. Relation: a = Abc, with 'a' being absorptivity, 'A' absorbance, 'b' path length in cm, and 'c' concentration in g/L.

    • Atomic Absorption (AA) Spectrophotometry: Technique where elements in a sample are atomized and measured based on their ability to absorb radiation when in a neutral state.

    • Bandpass: The specific range of wavelengths that a filter or monochromator allows through, measured at half the peak transmittance.

    • Beer's Law: Describes the linear relationship between concentration and absorbance; expressed as A = abc. States that higher concentration leads to increased absorption.

    • Bioluminescence: Light emission due to an electron's return to a lower energy level following a biochemical reaction, enhanced by enzymes or photoproteins.

    • Blank: A comparison solution in spectrophotometry that mirrors the test solutions except for the analyte being measured, ensuring accuracy in measurement.

    • Chemiluminescence: Light emitted from an electron transitioning back down to a lower energy level, triggered by a chemical reaction, not light exposure.

    • Electrochemiluminescence: Light emission resulting from an electrochemical reaction at an electrode's surface, also causing electrons to drop to a lower energy state.

    • Flow Cytometry: A technique that analyzes physical or chemical characteristics of cells or particles as they flow individually through a measuring device.

    • Fluorescence: Emission of light when a molecule absorbs light and re-emits it at a longer wavelength upon returning to the ground state, triggered by a photo excitation.

    • Fluorometry: Method of measuring fluorescence emitted by substances, involving the detection of light after absorption and re-emission processes.

    • Light: Energy form transmitted in electromagnetic waves, characterized by frequency and wavelength; consists of photons, whose energy inversely relates to wavelength.

    • Light Scattering: Interaction of light with particles in a solution, causing a change in light direction due to this interaction.

    • Molar Absorptivity: Similar to absorptivity but defined for a 1 mol/L solution, mathematically expressed as ε = Abc.

    • Nephelometry: Method for detecting and measuring light scattered towards a detector not in the direct light path; often measures at right angles to the light beam.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    Explore essential definitions related to absorbance and absorptivity in chemistry. This quiz will help you understand the relationship between light and concentration in various compounds. Test your knowledge of these fundamental concepts and their implications in scientific studies.

    More Like This

    Use Quizgecko on...
    Browser
    Browser