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 caelld neutrons. That core is surrounded by negatively charged particles called electrons. The iditntey of an atom is determined only by the number of protons in its nucleus. Hydrogen is hogredyn because it has just one porotn, 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 srrtuutce? We can't see portnos, neutrons, or electrons. So, we do a bunch of experiments and dovelep a model for what we think is there. Then we do some more epereitmnxs 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 dctreuioms 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 mrray them, we probably would. But ernlectos are weird. They appear to beavhe either as particles, like little baseballs, or as wvaes, like water waves, ddniepeng on the ermixpenet 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 uriattencny is part of our model of the electron. So, we can't pinpoint them, fine. But we can say there's a certain plbtairoiby 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 strats to deecsrae more or less exponentially, which menas that while it will approach zero, it'll never actually hit zero. So, in every atom, there is some slmal, 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 usinerve. But mostly electrons stay csole to their nuceuls as clouds of naigvtee charged density that shift and move with time. How electrons from one atom ierantct with electrons from another determines almost everything. Atoms can give up their electrons, surrendering them to other aotms, 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.

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 ______ neutrons. That core is surrounded by negatively charged particles called electrons. The ________ of an atom is determined only by the number of protons in its nucleus. Hydrogen is ________ 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 _________? We can't see _______, neutrons, or electrons. So, we do a bunch of experiments and _______ a model for what we think is there. Then we do some more ___________ 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 __________ 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 _____ them, we probably would. But _________ are weird. They appear to ______ either as particles, like little baseballs, or as _____, like water waves, _________ on the __________ 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 ___________ is part of our model of the electron. So, we can't pinpoint them, fine. But we can say there's a certain ___________ 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 ______ to ________ more or less exponentially, which _____ that while it will approach zero, it'll never actually hit zero. So, in every atom, there is some _____, 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 ________. But mostly electrons stay _____ to their _______ as clouds of ________ charged density that shift and move with time. How electrons from one atom ________ with electrons from another determines almost everything. Atoms can give up their electrons, surrendering them to other _____, 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.

Solution

  1. protons
  2. waves
  3. nucleus
  4. negative
  5. uncertainty
  6. experiments
  7. probability
  8. electrons
  9. identity
  10. small
  11. means
  12. structure
  13. behave
  14. interact
  15. starts
  16. develop
  17. atoms
  18. called
  19. marry
  20. decrease
  21. close
  22. proton
  23. democritus
  24. hydrogen
  25. experiment
  26. universe
  27. depending

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

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  2. approach
  3. atom
  4. atomic
  5. atoms
  6. baseballs
  7. bc
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  16. chemistry
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  57. lots
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  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