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  • Khan Academy
    If you're seeing this message, it means we're having trouble loading external resources on our website If you're behind a web filter, please make sure that the domains * kastatic org and * kasandbox org are unblocked
  • Ions - Khan Academy
    How many protons and neutrons does it contain and what is its charge? We figured out its charge We know the protons By definition platinum has 78 protons But what about its neutrons? Well protons plus neutrons is going to be equal to our mass number It's going to be equal to 195 So we have 78 protons plus I'll say N for neutrons is equal
  • Khan Academy
    In this video we're going to practice using the mass number equation This equation represents the fact that the mass number of an atom is equal to its number of protons plus its number of neutrons Let's use the mass number equation to answer the following question How many neutrons are in an isotope of sodium with the following notation?
  • Isotopes - Khan Academy
    Isotopes are atoms of the same element with different numbers of neutrons Because they contain different numbers of neutrons, isotopes have different atomic masses The average atomic mass of an element is calculated by taking the weighted average mass of the element's naturally occurring isotopes
  • Khan Academy
    Plus de 6 000 vidéos et des dizaines de milliers d'exercices interactifs sont disponibles du niveau primaire au niveau universitaire Découvrez l'accès par classe très utile pour vos révisions d'examens ! Khan Academy est une organisation à but non lucratif
  • Protons, neutrons, and electrons in atoms - Khan Academy
    Atoms are made up of three types of subatomic particles: protons, neutrons, and electrons Protons and neutrons are found in the nucleus, the dense region at the center of an atom Electrons are found outside the nucleus Protons are positively charged and have a mass of about 1 u
  • Isotope composition: Counting protons, electrons, and neutrons
    Practice finding the number of protons, electrons, and neutrons for different isotopes
  • Khan Academy
    Farklı izotoplar için proton, elektron ve nötron sayılarını bulma alıştırması yapın


















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