Sources of Light

Sources of Light

Sources of Light How is light produced? Luminous objects, produce their own light E.g. the sun Non-luminous objects, do not

produce their own light E.g. the moon Most objects are non-luminous Sources of Light 1. Incandescence The production of light

from high heat E.g. an incandescent bulb or a candle 2. Electric Discharge Electric current passing through a gas.

E.g. a street lamp or neon sign 3. Phosphorescence Absorption of UV radiation followed by the emission of visible light over an extended period

of time. E.g. glow-in-the-dark toys 4. Fluorescence The immediate emission of visible light E.g. fluorescent bulbs

(tube or compact) 5. Fluorescence continued The bulb is filled with mercury gas and coated with a phosphor Electricity causes the mercury atoms to emit

UV radiation, which are absorbed by the phosphor and released immediately. 6. Chemiluminescence Chemical reaction creates light

No heat produced E.g. glowstick 7. Bioluminescence Living organisms performing chemiluminescenc e

E.g. fireflies, angler fish 8. Triboluminescence Scratching, crushing, or rubbing certain crystals creates light (friction)

E.g. rubbing two sugar cubes together or biting Wint -O-Green lifesavers 9. LEDs (light emitting diodes) An electric current flowing through a

semiconductor Very energy efficient E.g. Christmas lights, some TVs

Recently Viewed Presentations

  • Grids/CI for Scholarly Research and application to Chemical

    Grids/CI for Scholarly Research and application to Chemical

    Distributed Science Methodology publishes all steps in a new electronic logbook capturing scientific process (data analysis) as a rich cloud of resources including emails, PPT, Wikis as well as databases, compiler options, build time/runtime configuration… Community (?
  • Flexible Spending Account with Benny Card What is

    Flexible Spending Account with Benny Card What is

    Eligible Expenses. Per IRS regulations, the following, while not intended to be complete, illustrates examples of eligible medical or medical-related expenses.Expenses must be incurred during the Plan Year from which you are requesting reimbursement. Expenses are considered incurred when service...
  • Chordates - Teacher.co.ke

    Chordates - Teacher.co.ke

    Phylum Chordata. By the end of the Cambrian period, 540 million years ago, an astonishing variety of animals inhabited Earth's oceans. One of these types of animals gave rise to vertebrates, one of the most successful groups of animals.
  • H S NNG LC Cng ty TNHH Xut

    H S NNG LC Cng ty TNHH Xut

    Vật liệu xây dựng dân dụng được các hộ gia đình tin dùng để bảo vệ nhà cửa và tài sản. Các sản phẩm Grace gồm có lớp phủ mái chống thấm, mái che dẻo cho các cửa sổ, cửa...
  • Topic Two Mrs. Daniel- Algebra 1 Table Contents:

    Topic Two Mrs. Daniel- Algebra 1 Table Contents:

    Lesson 4.1:Identifying & Graphing SequencesEssential Question: What is a sequence and how are sequences and functions related? Vocab. Sequence = a list of numbers in a specific order. Term = each element/number in a sequence. Explicit Rule
  • PBLA & Edulinc: Supporting Teachers & Learners

    PBLA & Edulinc: Supporting Teachers & Learners

    PBLA & Edulinc: Supporting Teachers & Learners Portfolio-based Language Assessment (PBLA) and the LearnIT2teach Projects are two settlement language training initiatives funded by Immigration, Refugees and Citizenship Canada.
  • Koloidi I Makromolekuli

    Koloidi I Makromolekuli

    KOLOIDI I MAKROMOLEKULI Sistemi u kojima je jedna ili više supstancija u većoj ili manjoj meri usitnjena i ravnomerno raspoređena u okružujućoj sredini, su disperzni sistemi.
  • Access Accountancy Work Insight Programme

    Access Accountancy Work Insight Programme

    Access Accountancy Work Insight Programme. ... Nottingham. Sutton . Poole. We are running the programme across 14 offices nationally - we started with 1 cohort in London in 2017, 11 cohorts in 2018, with 14 planned for 2019. Activities.