full transcript

From the Ted Talk by George Zaidan and Charles Morton: The uncertain location of electrons

Unscramble the Blue Letters

You probably know that all stuff is made up of atoms and that an atom is a really, really, really, really tiny particle. Every atom has a core, which is made up of at least one positively charged particle called a proton, and in most cases, some number of neutral particles called neutrons. That core is surrounded by negatively charged particles called electrons. The identity of an atom is dierenmetd only by the number of protons in its nucleus. Hydrogen is hydrogen because it has just one ptroon, carbon is carbon because it has six, gold is gold because it has 79, and so on. Indulge me in a momentary tangent. How do we know about atomic structure? We can't see protons, neutrons, or electrons. So, we do a bnuch of extmepneris and develop a model for what we think is there. Then we do some more experiments and see if they agree with the model. If they do, great. If they don't, it might be time for a new mdoel. We've had lots of very different models for atoms since Democritus in 400 BC, and there will almost certainly be many more to come. Okay, tangent over. The cores of atoms tend to stick together, but electrons are free to move, and this is why chemists love electrons. If we could marry them, we probably would. But electrons are weird. They appear to behave either as particles, like little baseballs, or as waves, like water waves, denpiedng on the experiment that we pforrem. One of the wesirdet things about etlecnors is that we can't exactly say where they are. It's not that we don't have the equipment, it's that this uncertainty is part of our model of the electron. So, we can't pinpoint them, fine. But we can say there's a certain probability of finding an elcreotn in a given space around the nuucels. And that means that we can ask the following question: If we drew a shape around the nucleus such that we would be 95% sure of finding a given electron within that shape, what would it look like? Here are a few of these shapes. Chemists call them orbitals, and what each one looks like depends on, among other things, how much energy it has. The more energy an orbital has, the farther most of its density is from the nucleus. By they way, why did we pick 95% and not 100%? Well, that's another quirk of our model of the electron. Past a certain diacstne from the nucleus, the probability of finding an electron starts to decrease more or less exponentially, which means that while it will approach zero, it'll never actually hit zero. So, in every atom, there is some small, but non-zero, probability that for a very, very short period of time, one of its electrons is at the other end of the known universe. But mostly electrons stay close to their nucleus as clouds of negative crhgaed density that sfiht and move with time. How electrons from one atom interact with electrons from another determines almost everything. Atoms can give up their electrons, surrendering them to other atoms, or they can sarhe electrons. And the dnimcays of this scaiol ntorewk are what make chemistry interesting. From plain old rcoks to the beautiful ctmelxoipy of life, the nature of everything we see, hear, smell, taste, tcouh, and even feel is determined at the amoitc lveel.

Open Cloze

You probably know that all stuff is made up of atoms and that an atom is a really, really, really, really tiny particle. Every atom has a core, which is made up of at least one positively charged particle called a proton, and in most cases, some number of neutral particles called neutrons. That core is surrounded by negatively charged particles called electrons. The identity of an atom is __________ only by the number of protons in its nucleus. Hydrogen is hydrogen because it has just one ______, carbon is carbon because it has six, gold is gold because it has 79, and so on. Indulge me in a momentary tangent. How do we know about atomic structure? We can't see protons, neutrons, or electrons. So, we do a _____ of ___________ and develop a model for what we think is there. Then we do some more experiments and see if they agree with the model. If they do, great. If they don't, it might be time for a new _____. We've had lots of very different models for atoms since Democritus in 400 BC, and there will almost certainly be many more to come. Okay, tangent over. The cores of atoms tend to stick together, but electrons are free to move, and this is why chemists love electrons. If we could marry them, we probably would. But electrons are weird. They appear to behave either as particles, like little baseballs, or as waves, like water waves, _________ on the experiment that we _______. One of the ________ things about _________ is that we can't exactly say where they are. It's not that we don't have the equipment, it's that this uncertainty is part of our model of the electron. So, we can't pinpoint them, fine. But we can say there's a certain probability of finding an ________ in a given space around the _______. And that means that we can ask the following question: If we drew a shape around the nucleus such that we would be 95% sure of finding a given electron within that shape, what would it look like? Here are a few of these shapes. Chemists call them orbitals, and what each one looks like depends on, among other things, how much energy it has. The more energy an orbital has, the farther most of its density is from the nucleus. By they way, why did we pick 95% and not 100%? Well, that's another quirk of our model of the electron. Past a certain ________ from the nucleus, the probability of finding an electron starts to decrease more or less exponentially, which means that while it will approach zero, it'll never actually hit zero. So, in every atom, there is some small, but non-zero, probability that for a very, very short period of time, one of its electrons is at the other end of the known universe. But mostly electrons stay close to their nucleus as clouds of negative _______ density that _____ and move with time. How electrons from one atom interact with electrons from another determines almost everything. Atoms can give up their electrons, surrendering them to other atoms, or they can _____ electrons. And the ________ of this ______ _______ are what make chemistry interesting. From plain old _____ to the beautiful __________ of life, the nature of everything we see, hear, smell, taste, _____, and even feel is determined at the ______ _____.

Solution

  1. depending
  2. distance
  3. experiments
  4. touch
  5. shift
  6. complexity
  7. atomic
  8. electrons
  9. determined
  10. charged
  11. rocks
  12. dynamics
  13. nucleus
  14. electron
  15. social
  16. weirdest
  17. bunch
  18. model
  19. level
  20. proton
  21. perform
  22. network
  23. share

Original Text

You probably know that all stuff is made up of atoms and that an atom is a really, really, really, really tiny particle. Every atom has a core, which is made up of at least one positively charged particle called a proton, and in most cases, some number of neutral particles called neutrons. That core is surrounded by negatively charged particles called electrons. The identity of an atom is determined only by the number of protons in its nucleus. Hydrogen is hydrogen because it has just one proton, carbon is carbon because it has six, gold is gold because it has 79, and so on. Indulge me in a momentary tangent. How do we know about atomic structure? We can't see protons, neutrons, or electrons. So, we do a bunch of experiments and develop a model for what we think is there. Then we do some more experiments and see if they agree with the model. If they do, great. If they don't, it might be time for a new model. We've had lots of very different models for atoms since Democritus in 400 BC, and there will almost certainly be many more to come. Okay, tangent over. The cores of atoms tend to stick together, but electrons are free to move, and this is why chemists love electrons. If we could marry them, we probably would. But electrons are weird. They appear to behave either as particles, like little baseballs, or as waves, like water waves, depending on the experiment that we perform. One of the weirdest things about electrons is that we can't exactly say where they are. It's not that we don't have the equipment, it's that this uncertainty is part of our model of the electron. So, we can't pinpoint them, fine. But we can say there's a certain probability of finding an electron in a given space around the nucleus. And that means that we can ask the following question: If we drew a shape around the nucleus such that we would be 95% sure of finding a given electron within that shape, what would it look like? Here are a few of these shapes. Chemists call them orbitals, and what each one looks like depends on, among other things, how much energy it has. The more energy an orbital has, the farther most of its density is from the nucleus. By they way, why did we pick 95% and not 100%? Well, that's another quirk of our model of the electron. Past a certain distance from the nucleus, the probability of finding an electron starts to decrease more or less exponentially, which means that while it will approach zero, it'll never actually hit zero. So, in every atom, there is some small, but non-zero, probability that for a very, very short period of time, one of its electrons is at the other end of the known universe. But mostly electrons stay close to their nucleus as clouds of negative charged density that shift and move with time. How electrons from one atom interact with electrons from another determines almost everything. Atoms can give up their electrons, surrendering them to other atoms, or they can share electrons. And the dynamics of this social network are what make chemistry interesting. From plain old rocks to the beautiful complexity of life, the nature of everything we see, hear, smell, taste, touch, and even feel is determined at the atomic level.

Frequently Occurring Word Combinations

Important Words

  1. agree
  2. approach
  3. atom
  4. atomic
  5. atoms
  6. baseballs
  7. bc
  8. beautiful
  9. behave
  10. bunch
  11. call
  12. called
  13. carbon
  14. cases
  15. charged
  16. chemistry
  17. chemists
  18. close
  19. clouds
  20. complexity
  21. core
  22. cores
  23. decrease
  24. democritus
  25. density
  26. depending
  27. depends
  28. determined
  29. determines
  30. develop
  31. distance
  32. drew
  33. dynamics
  34. electron
  35. electrons
  36. energy
  37. equipment
  38. experiment
  39. experiments
  40. exponentially
  41. feel
  42. finding
  43. fine
  44. free
  45. give
  46. gold
  47. great
  48. hear
  49. hit
  50. hydrogen
  51. identity
  52. indulge
  53. interact
  54. interesting
  55. level
  56. life
  57. lots
  58. love
  59. marry
  60. means
  61. model
  62. models
  63. momentary
  64. move
  65. nature
  66. negative
  67. negatively
  68. network
  69. neutral
  70. neutrons
  71. nucleus
  72. number
  73. orbital
  74. orbitals
  75. part
  76. particle
  77. particles
  78. perform
  79. period
  80. pick
  81. pinpoint
  82. plain
  83. positively
  84. probability
  85. proton
  86. protons
  87. quirk
  88. rocks
  89. shape
  90. shapes
  91. share
  92. shift
  93. short
  94. small
  95. smell
  96. social
  97. space
  98. starts
  99. stay
  100. stick
  101. structure
  102. stuff
  103. surrendering
  104. surrounded
  105. tangent
  106. taste
  107. tend
  108. time
  109. tiny
  110. touch
  111. uncertainty
  112. universe
  113. water
  114. waves
  115. weird
  116. weirdest