Modelos atómicos

00:06:36
https://www.youtube.com/watch?v=KhNHKg60p7g

Résumé

TLDRThe video explains the concepts of atomic number and mass number in a simple and concise manner. The atomic number, represented by the letter 'Z', indicates the number of protons in an atom's nucleus, and because atoms are neutral, it also indicates the number of electrons. The mass number, represented by the letter 'A', indicates the total number of subatomic particles in the nucleus (protons plus neutrons). Using sodium-23 and sulfur-32 as examples, the video demonstrates how to calculate the number of neutrons by subtracting the atomic number from the mass number. This brief video concludes with a reminder of the representations of atomic and mass numbers.

A retenir

  • ⚛️ Atomic number ('Z') is the number of protons.
  • 🔢 Mass number ('A') is the total of protons and neutrons.
  • 🔬 Atoms are electrically neutral: protons = electrons.
  • 🧮 Number of neutrons = Mass number - Atomic number.
  • 🌟 Sodium example: 23-11, has 11 protons.
  • 🧊 Sulfur example: 32-16, has 16 neutrons.
  • 🧪 Atomic structure basics explained.
  • 📘 Understanding atomic and mass numbers helps in chemistry.
  • 🧩 Protons determine the element's identity.
  • 🔍 Analyze atomic structure to learn element properties.

Chronologie

  • 00:00:00 - 00:06:36

    The video provides an educational overview of atomic numbers and mass numbers in chemistry. It begins by defining the atomic number as the number of protons in the nucleus of an atom, represented by the letter Z. This number also indicates the number of electrons in a neutral atom. The mass number, represented by the letter A, is the total count of protons and neutrons. A formula is provided that the mass number equals the atomic number plus the number of neutrons. The video uses sodium (23-11) as an example, explaining how to find the number of neutrons by subtracting the atomic number from the mass number. Another example with sulfur (32-16) reiterates this concept. The conclusion reinforces these definitions, stating that the atomic number reflects the number of protons and electrons, while the mass number is the sum of protons and neutrons. The video encourages viewers to continue learning about chemistry.

Carte mentale

Mind Map

Questions fréquemment posées

  • What does the atomic number represent?

    The atomic number represents the number of protons in an atom's nucleus.

  • What does the mass number represent?

    The mass number represents the total number of protons and neutrons in the nucleus.

  • How do you calculate the number of neutrons in an atom?

    Subtract the atomic number from the mass number to get the number of neutrons.

  • What is indicated by the letter 'Z'?

    The letter 'Z' indicates the atomic number, which is the number of protons.

  • What is indicated by the letter 'A'?

    The letter 'A' indicates the mass number, which is the sum of protons and neutrons.

  • Is the atom electrically neutral?

    Yes, because it has the same number of protons (positive particles) as electrons (negative particles).

  • How many protons does sodium have?

    Sodium has 11 protons.

  • What is the mass number of sodium?

    The mass number of sodium is 23.

  • How many neutrons does sulfur have in sulfur-32?

    Sulfur in sulfur-32 has 16 neutrons (32-16).

  • Why is the atomic number equal to the number of electrons?

    Because atoms are electrically neutral, so the number of protons equals the number of electrons.

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Sous-titres
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Défilement automatique:
  • 00:00:00
    Does the atomic number and the mass number
  • 00:00:01
    sound like Mandarin Chinese? yes?
  • 00:00:04
    If you change the channel you will miss a
  • 00:00:06
    unique opportunity to learn what they
  • 00:00:08
    are and what they are for, and all this in
  • 00:00:11
    less than five minutes, so let's do it.
  • 00:00:28
    Given any element, let's call it x,
  • 00:00:32
    its atomic number will be represented
  • 00:00:34
    with the letter z. This number indicates
  • 00:00:38
    the number of protons that an atom has
  • 00:00:40
    in its nucleus.
  • 00:00:50
    The letter a represents the mass number, which
  • 00:00:53
    indicates the number of subatomic particles
  • 00:00:54
    in the nucleus, that is,
  • 00:00:56
    the number of protons and neutrons.
  • 00:01:02
    Since atoms are electrically neutral,
  • 00:01:04
    since they have the same number of
  • 00:01:06
    positive as negative particles,
  • 00:01:08
    the atomic number will also indicate
  • 00:01:10
    the number of electrons in a
  • 00:01:11
    chemical element.
  • 00:01:18
    Since z is equal to the number of
  • 00:01:21
    protons in an atom, we can say that the
  • 00:01:24
    mass number is equal to the atomic
  • 00:01:27
    number plus the number of neutrons.
  • 00:01:31
    Let's look at an example of the case of sodium 23-11.
  • 00:01:34
    11 is the atomic number of sodium.
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    That means it has 11 protons, and
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    therefore 11 electrons.
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    To calculate its number of neutrons
  • 00:01:50
    we will have to subtract its mass number,
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    23, minus its 11 protons.
  • 00:02:02
    Pause this video and try to get the
  • 00:02:04
    number of subatomic particles
  • 00:02:07
    of sulfur 32-16.
  • 00:02:17
    16 is the atomic number of sulfur, so
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    it will have 16 protons and
  • 00:02:23
    16 electrons
  • 00:02:26
    We will obtain a number of neutrons
  • 00:02:28
    by subtracting their mass number,
  • 00:02:30
    32, minus the number of protons, 16.
  • 00:02:38
    As you have been able to check the atomic
  • 00:02:40
    number and the mass number, they no longer
  • 00:02:42
    have secrets for you. Remember, the atomic
  • 00:02:45
    number is represented by the letter z,
  • 00:02:48
    and indicates the number of protons in
  • 00:02:50
    the nucleus. Since the atom is
  • 00:02:51
    electrically neutral it will
  • 00:02:53
    also indicate the number of
  • 00:02:55
    electrons in the cortex.
  • 00:02:57
    On the other hand, the mass number
  • 00:02:59
    is represented by the letter a, which
  • 00:03:02
    indicates the number of subatomic particles
  • 00:03:04
    in the nucleus, that is, the number of
  • 00:03:05
    protons + neutrons. I hope this video
  • 00:03:09
    has helped you. See you in the next
  • 00:03:11
    one. May chemistry be with you!
Tags
  • Atomic number
  • Mass number
  • Protons
  • Neutrons
  • Electrons
  • Subatomic particles
  • Chemistry basics
  • Atomic structure
  • Isotopes