Half-life | Physics | Khan Academy

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  • Опубліковано 26 чер 2024
  • Half-life is the time required for half of a radioactive sample to decay. Half-life cannot be changed-nuclei cannot be forced to decay faster or slower. Additionally, we cannot predict when an individual nucleus will decay. However, when analyzing a large sample containing many nuclei, half-life allows us to predict how much of the sample will remain after a given amount of time. This is useful for radiometric dating.
    Sections:
    00:00 - Intro
    00:34 - What is half-life?
    03:26 - Coin toss analogy
    05:50 - Radioactive decay is spontaneous
    06:37 - Why care about half-life?
    07:20 - Decay graph
    08:30 - Radiometric dating
    ------------------
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КОМЕНТАРІ • 22

  • @subjectnether959
    @subjectnether959 4 місяці тому +14

    "Gordon doesnt need to hear all this, he's a highly trained professional."

  • @user-pg2zc4oi6r
    @user-pg2zc4oi6r 4 місяці тому +22

    Clicked cause of the game, stayed out of curiosity. Wasn't dissapointed.

    • @A_Good_Boy.
      @A_Good_Boy. 4 місяці тому +1

      do you know? they copied the main place from counter strike half-life game in the current Loki season 2

    • @Nived_69
      @Nived_69 2 місяці тому

      @@A_Good_Boy. i thought they just had a copy of the stun baton

  • @UNITEDNATIONSAREAWESOME
    @UNITEDNATIONSAREAWESOME 4 місяці тому +8

    Gordon doesn’t need to hear all of this, he’s a highly trained professional

  • @Mahesh_Shenoy
    @Mahesh_Shenoy 4 місяці тому +7

    ‘Please, leave me alone until after the experiment!’

  • @ibraheimsalam4345
    @ibraheimsalam4345 4 місяці тому +4

    Well explained

  • @CristuelCasto
    @CristuelCasto 4 місяці тому +5

    It's a great game.

  • @ipalomino2182
    @ipalomino2182 4 місяці тому +3

    Nice video, thanks.
    But how do we know that the half-live of C14 is 5730 years? Radioactivity was discovered on the 19th century, right?

    • @christinejackson6630
      @christinejackson6630 4 місяці тому +1

      True, but the decay of any radioisotope follows an exponential decay curve as shown at 8:42. So, even if we’ve observed a sample for less than one full half-life, we can measure how much of the parent remains after that time. Then we can extrapolate the rest of the decay curve and determine the radioisotope’s half-life.

  • @Manigo1743
    @Manigo1743 8 днів тому

    But how do we know that uranium has a half-life of 4.5B years? It is not like we can sit around and wait to see how long it takes for half of it to disappear. Even with a large amount, and waiting for something like 100 years, would it even be noticable?

  • @rainingng7960
    @rainingng7960 4 місяці тому +6

    λ

  • @scarletspidernz
    @scarletspidernz 4 місяці тому +3

    Half Life 3 Confirmed

  • @iwuvu5940
    @iwuvu5940 Місяць тому +1

    Ah yes, my favorite video game ever

  • @manoprakash2674
    @manoprakash2674 3 місяці тому

    That was awesome. Keep up the good work.

  • @gagelol
    @gagelol 24 дні тому

    3 months ago is clutch

  • @user-hxh12369
    @user-hxh12369 4 місяці тому

    Wow 😲.

  • @FOOTBALL-hw1qy
    @FOOTBALL-hw1qy 4 місяці тому +1

    Why half life is 5730? Why not something else? Cz the atmosphere around the globe is not the same!

  • @annettegutierrez3715
    @annettegutierrez3715 4 місяці тому +2

    POV: VALVe copyright infringement???

  • @manjugagare802
    @manjugagare802 4 місяці тому

    Wouldn't this apply that all carbon atoms should decay into nitrogen

  • @SajiSNairNair-tu9dk
    @SajiSNairNair-tu9dk 4 місяці тому +1

    😂👉jest 🕵️chintamani 🥰