Pratique du Shadowing: Elements | Middle school chemistry | Khan Academy - Apprendre l'anglais à l'oral avec la vidéo
Création de la leçon...
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Think about all the thousands of books and poems and articles and dictionaries and encyclopedias and textbooks and so much more.
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All those English writings are fundamentally made of what?
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26 letters.
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And yeah, some spaces, but that's it.
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These 26 letters forms the building block of almost every single thing, all the uncountable words and sentences that you can make.
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Now, guess what?
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Turns out, our nature is similar.
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Almost everything that you can touch and taste and smell
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and feel around you from the germs to microbes to stuff like cats
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and dogs to oceans and mountains and even planets and stars.
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Turns out, All of these are also made from just a few building blocks, about a hundred of them.
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Each square over here represents a building block, and we'll talk a little bit about how we arrange them and stuff.
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But these building blocks are called the elements.
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And that's what we're going to talk about in this video.
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So let's do that.
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First of all, these elements, the building blocks, are also called pure substances.
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And like I said earlier, they make up almost all the matter around us.
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hydrogen and oxygen and consider any living being like yourself then you are mostly made of six Elements.
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Oxygen, Carbon, Hydrogen, Nitrogen, Calcium, and Phosphorus.
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I mean, there are other elements, but these mostly make it up.
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And just to give you another example, if you consider any rock, then they're mostly made of five elements: Silicon,
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Oxygen, Aluminium, Magnesium, and Iron.
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Don't worry about remembering the names of these elements for now.
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What's important, and I keep repeating because it's so important, is that almost all the matter in the universe is made from these elements.
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So to study matter, we need to study these elements.
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So let's do that.
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We arrange these elements in this particular form and we call this the periodic table.
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It might seem daunting at first, but let's look at it, okay?
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So first of all, you can see that each element gets a square and a number.
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So, element number one is hydrogen.
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Element number two is over here, helium.
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Element number three is lithium.
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Element number four is beryllium and so on and so forth.
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What we want to notice over here is that each element has a symbol, kind of an abbreviation.
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Now for some elements, that's basically the first letter of the word, H for hydrogen.
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B for boron, C for carbon, N for nitrogen, and so on and so forth.
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And notice we always use capital letters.
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But what about other elements which start with the same letter?
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For example, helium.
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How do we ensure we don't confuse it with hydrogen?
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Well, we use first two letters, so HE.
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Similarly, for calcium, to make sure we don't confuse it with carbon, we use the first two letters, CA, and so on and so forth.
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But what's important again over here is to notice how we write that.
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the first letter is capital over here, the second letter is small.
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So we'll never write helium this way, where both are capital, and we'll never write it this way, where both are small.
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We'll always write it as first letter capital, second letter small, and that's always the case.
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Alright, these make sense, but what about sodium?
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Sodium is Na, what's going on over here?
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And then there's more such stuff.
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So for example, gold is Au.
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Tungsten, which is used in the filament of our bulbs, is W.
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And lead is PB, what's going on over here?
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Well, humanity has known about these elements for a long time now.
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And some of these symbols are taken from the old names from different languages like Greek, Latin, Arabic, German, and so on.
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Na stands for natrium, a Latin word for sodium.
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AU comes from Aurum.
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PB comes from Plumbum, the Latin word for lead.
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Fun fact, earlier pipes in the Roman Empire were made from lead
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and therefore people who used to fix those pipes were called Plumbers and the name is stuck today.
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And W comes from the German Wolfram.
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Now again, you might be thinking, "Oh my god, how am I supposed to remember all of this?" Don't worry, we don't have to do that.
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As we start talking about some of the common elements over and over again, we'll start So, in summary, all the matter that you see,
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almost everything in the universe is made of a few, about a hundred elements, which we also call the pure substances.
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They're arranged this way in what we call the periodic table.
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And just like how learning the English language is basically figuring
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out how we can combine these different letters to form very interesting words and sentences,
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the trick to learning about matter is learning how we can combine these different elements to form interesting new things.
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before?
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Well, imagine we had a hundred different kinds of Legos with us.
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Then by combining them in different combinations, you can build up almost anything you want.
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And now you can imagine some of these Lego structures are like mountains and others are like cats.
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And we can build whatever we want.
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We can let our imagination lose over here, which is pretty awesome.
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But if you break them all down into their basic pieces, you get back your elements.
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Vocabulaire et conseils d’expression pour cette leçon
Les mots qui reviennent le plus souvent : element, letter, hydrogen, block, word. Cette vidéo contient 74 phrases et 902 mots à répéter en shadowing. La partie parlée dure 5:10. Le locuteur parle à un rythme naturel d’environ 174 mots par minute, proche d’une conversation courante. 86 % des mots font partie des 3 000 mots les plus courants en anglais ; le reste mérite d’être vu avant de commencer.
Vocabulaire clé de cette vidéo
Les 15 mots les plus avancés de la vidéo, avec leur prononciation et leur sens :
| Mot | Prononciation | Sens |
|---|---|---|
| litter nom | /ˈlɪt.ɚ/ | litière |
| hydrogen nom | /ˈhaɪdɹəd͡ʒ(ə)n/ | hydrogène |
| helium nom | /ˈhiː.li.əm/ | hélium |
| sodium nom | /ˈsəʊ.di.əm/ | sodium |
| arrange verbe | /əˈɹeɪnd͡ʒ/ | arranger, organiser |
| combine verbe | /kəmˈbaɪn/ | combiner |
| oxygen nom | /ˈɑksɪd͡ʒən/ | oxygène |
| periodic adjectif | /ˌpɪɹiˈɑdɪk/ | périodique |
| confuse verbe | /kənˈfjuːz/ | rendre perplexe, confondre |
| nitrogen nom | /ˈnaɪ.tɹə.d͡ʒən/ | azote |
| calcium nom | /ˈkælsi.əm/ | calcium |
| substance nom | /ˈsʌbstəns/ | substance |
| pipe nom | /ˈpaɪp/ | cornemuse |
| symbol nom | /ˈsɪmbəl/ | symbole |
| abbreviation nom | /əˌbɹi.viˈeɪ.ʃn̩/ | abréviation |
Les verbes à particule que vous entendrez
| Mot | Prononciation | Sens |
|---|---|---|
| turn out verbe | se finir, se terminer | |
| build up verbe | s'accumuler, s'entasser | |
| get back verbe | retourner | |
| make up verbe | /ˌmeɪk ˈʌp/ | constituer, composer |
La grammaire de cette vidéo
Les structures que le locuteur utilise le plus, avec les mots exacts de la vidéo :
| Structure | Dans la vidéo |
|---|---|
| Voix passive be + participe passé — l’accent est mis sur ce qui arrive, pas sur qui le fait | are also made · are called · are also called |
| Propositions relatives who / which + proposition — une précision sur une personne ou une chose | Tungsten, which is · people who used · here, which is |
| Possibilité avec « might / may » might/may + verbe — quelque chose de possible mais pas certain | might seem · might be |
| Verbe + -ing enjoy, keep, stop… + -ing — les verbes suivis de la forme en -ing | keep repeating · start talking |
Prononciation à surveiller
Le locuteur utilise 13 contractions et formes réduites, comme don't, we'll, they're. Prononcez-les sous leur forme courte, telles que vous les entendez.
- Les sons « sh » et « zh »: abbreviation /əˌbɹi.viˈeɪ.ʃn̩/, combinations /kɑmbɪˈneɪʃənz/, dictionary /ˈdɪk.ʃəˌnɛ.ɹi/, imagination /ɪˌmæd͡ʒəˈneɪʃən/
- Mots longs — placez bien l’accent: periodic /ˌpɪɹiˈɑdɪk/, abbreviation /əˌbɹi.viˈeɪ.ʃn̩/, beryllium /bəˈɹɪl.i.əm/, encyclopedia /ɪnˌsaɪkləˈpidi.ə/, combinations /kɑmbɪˈneɪʃənz/
Les sons difficiles pour les francophones :
- /h/ — il se souffle, il n’est pas muet: hydrogen /ˈhaɪdɹəd͡ʒ(ə)n/, helium /ˈhiː.li.əm/, humanity /hjuˈmænɪti/
- /tʃ/ et /dʒ/ — à ne pas adoucir en « ch » et « j »: hydrogen /ˈhaɪdɹəd͡ʒ(ə)n/, arrange /əˈɹeɪnd͡ʒ/, oxygen /ˈɑksɪd͡ʒən/, nitrogen /ˈnaɪ.tɹə.d͡ʒən/, imagination /ɪˌmæd͡ʒəˈneɪʃən/
- /r/ anglais — langue recourbée, sans frotter la gorge: hydrogen /ˈhaɪdɹəd͡ʒ(ə)n/, arrange /əˈɹeɪnd͡ʒ/, periodic /ˌpɪɹiˈɑdɪk/, nitrogen /ˈnaɪ.tɹə.d͡ʒən/, abbreviation /əˌbɹi.viˈeɪ.ʃn̩/
Comment s’entraîner avec cette vidéo
- Écoutez la vidéo en entier une fois sans parler et notez les mots que vous ne connaissez pas.
- Commencez à la vitesse 0,75×, répétez phrase par phrase, puis revenez à la vitesse normale quand cela devient facile.
- Enregistrez-vous et comparez avec l’original, en faisant attention à des mots comme litter, hydrogen, helium.
Qu'est-ce que la technique du Shadowing ?
Le Shadowing est une technique d'apprentissage des langues fondée sur la science, développée à l'origine pour la formation des interprètes professionnels. Le principe est simple mais puissant : vous écoutez de l'anglais natif et le répétez immédiatement à voix haute — comme une ombre suivant le locuteur avec un décalage de 1 à 2 secondes. Les recherches montrent une amélioration significative de la précision de la prononciation, de l'intonation, du rythme, des liaisons, de la compréhension orale et de la fluidité.