CH7 – Mod\u00e8le ondulatoire et particulaire de la lumi\u00e8re<\/title>\n<style>\n:root{--bg:#f6f7fb;--ink:#111827;--muted:#4b5563;--accent:#7c3aed;--accent2:#0ea5e9;--card:#fff;--border:#e5e7eb;}\n*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;background:var(--bg);color:var(--ink);line-height:1.55}.wrap{max-width:1120px;margin:auto;padding:22px}header{background:linear-gradient(135deg,#312e81,#0891b2);color:white;border-radius:24px;padding:28px;box-shadow:0 16px 35px #0002}h1{margin:0;font-size:clamp(1.7rem,4vw,3.1rem)}.subtitle{font-size:1.1rem;opacity:.95;max-width:900px}.toolbar{display:flex;gap:12px;flex-wrap:wrap;margin-top:18px}.btn{display:inline-flex;align-items:center;gap:8px;background:#fff;color:#111827;text-decoration:none;border-radius:999px;padding:10px 15px;font-weight:700;border:1px solid #ffffff55;cursor:pointer}.btn.dark{background:#111827;color:white}.grid{display:grid;grid-template-columns:repeat(12,1fr);gap:16px;margin-top:18px}.card{grid-column:span 12;background:var(--card);border:1px solid var(--border);border-radius:22px;padding:20px;box-shadow:0 10px 28px #0000000d}@media(min-width:820px){.half{grid-column:span 6}.third{grid-column:span 4}.two{grid-column:span 8}}h2{margin-top:0;color:#312e81}h3{color:#0f172a}.formula{background:#f3f4f6;border:1px solid #c7d2fe;border-left:6px solid var(--accent);padding:14px;border-radius:14px;font-size:1.12rem;text-align:center;margin:12px 0}.memo{background:#fff7ed;border-left:6px solid #f97316}.exo{background:#f8fafc;border-left:6px solid #0ea5e9}.danger{background:#fef2f2;border-left:6px solid #ef4444}.ok{background:#ecfdf5;border-left:6px solid #10b981}table{border-collapse:collapse;width:100%;font-size:.95rem}td,th{border:1px solid #d1d5db;padding:8px;vertical-align:top}th{background:#eef2ff}.spectrum{height:80px;border-radius:16px;background:linear-gradient(90deg,#111 0 8%,#312e81 10%,#4f46e5 18%,#0ea5e9 30%,#22c55e 42%,#fde047 55%,#f97316 67%,#ef4444 78%,#111 90%);position:relative;margin:16px 0}.spectrum span{position:absolute;bottom:-26px;font-size:.85rem}.svgbox{width:100%;overflow:auto;text-align:center}svg{max-width:100%;height:auto}.quiz details{border:1px solid #ddd;border-radius:12px;margin:8px 0;padding:10px;background:white}.small{font-size:.9rem;color:var(--muted)}@media print{.toolbar,.no-print{display:none}body{background:white}.card,header{box-shadow:none}}\n<\/style><\/head><body><div class=\"wrap\">\n<header><h1>CH7 – Mod\u00e8le ondulatoire et particulaire de la lumi\u00e8re<\/h1><p class=\"subtitle\">Cours complet de premi\u00e8re sp\u00e9cialit\u00e9 : longueur d\u2019onde, photon, \u00e9nergie, absorption, \u00e9mission, niveaux d\u2019\u00e9nergie et spectres de raies.<\/p><div class=\"toolbar\"><button class=\"btn\" onclick=\"speakCourse()\">\ud83d\udd0a \u00c9couter le cours<\/button><button class=\"btn dark\" onclick=\"stopSpeak()\">Stop audio<\/button><a class=\"btn\" href=\"https:\/\/pcwallis.malo.wf\/wp-content\/uploads\/2026\/05\/chapitre_modele_lumiere_premiere_v1_cours_imprimable.pdf\" target=\"_blank\">\ud83d\udcc4 PDF cours imprimable<\/a><a class=\"btn\" href=\"https:\/\/pcwallis.malo.wf\/wp-content\/uploads\/2026\/05\/chapitre_modele_lumiere_premiere_v1_exercices_types.pdf\" target=\"_blank\">\ud83e\uddea PDF exercices types<\/a><\/div><\/header>\n<section class=\"grid\" id=\"courseText\">\n<div class=\"card memo\"><h2>\u00c0 retenir en 30 secondes<\/h2><p>La lumi\u00e8re peut \u00eatre d\u00e9crite comme une <b>onde<\/b>, avec une fr\u00e9quence f et une longueur d\u2019onde \u03bb, mais aussi comme un flux de <b>photons<\/b>. Chaque photon transporte une \u00e9nergie. Un atome absorbe ou \u00e9met seulement certaines \u00e9nergies : cela cr\u00e9e des <b>raies spectrales<\/b>, v\u00e9ritables signatures des \u00e9l\u00e9ments chimiques.<\/p><\/div>\n<div class=\"card half\"><h2>1. Mod\u00e8le ondulatoire<\/h2><p>La lumi\u00e8re est une onde \u00e9lectromagn\u00e9tique. Dans le vide ou dans l\u2019air, elle se propage \u00e0 la c\u00e9l\u00e9rit\u00e9 :<\/p><div class=\"formula\">c = 3,00 \u00d7 10<sup>8<\/sup> m\u00b7s<sup>\u22121<\/sup><\/div><div class=\"formula\">\u03bb = c \/ f<\/div><p>Avec \u03bb en m, c en m\u00b7s\u207b\u00b9 et f en Hz.<\/p><div class=\"spectrum\"><span style=\"left:18%\">UV<\/span><span style=\"left:37%\">Visible<\/span><span style=\"left:70%\">IR<\/span><\/div><p class=\"small\">Visible : environ 400 nm \u00e0 800 nm. Plus \u03bb est petite, plus la fr\u00e9quence et l\u2019\u00e9nergie sont grandes.<\/p><\/div>\n<div class=\"card half\"><h2>2. Mod\u00e8le particulaire : le photon<\/h2><p>Un photon est un paquet d\u2019\u00e9nergie transport\u00e9 par la lumi\u00e8re.<\/p><div class=\"formula\">E = h \u00d7 f et E = (h \u00d7 c) \/ \u03bb<\/div><p>Constante de Planck :<\/p><div class=\"formula\">h = 6,63 \u00d7 10<sup>\u221234<\/sup> J\u00b7s<\/div><p>Conversion utile :<\/p><div class=\"formula\">1 eV = 1,60 \u00d7 10<sup>\u221219<\/sup> J<\/div><\/div>\n<div class=\"card two\"><h2>3. Interaction lumi\u00e8re – mati\u00e8re<\/h2><p>Dans un atome, les \u00e9lectrons occupent des niveaux d\u2019\u00e9nergie bien pr\u00e9cis. Le niveau le plus bas est l\u2019\u00e9tat fondamental E<sub>0<\/sub>. Les niveaux plus hauts sont des \u00e9tats excit\u00e9s E<sub>1<\/sub>, E<sub>2<\/sub>, etc.<\/p><div class=\"svgbox\"><svg viewBox=\"0 0 620 230\"><line x1=\"80\" y1=\"25\" x2=\"80\" y2=\"205\" stroke=\"#111\"\/><text x=\"48\" y=\"35\">E<\/text><line x1=\"150\" y1=\"180\" x2=\"520\" y2=\"180\" stroke=\"#1d4ed8\" stroke-width=\"4\"\/><text x=\"530\" y=\"185\">E\u2080 \u00e9tat fondamental<\/text><line x1=\"150\" y1=\"115\" x2=\"520\" y2=\"115\" stroke=\"#1d4ed8\" stroke-width=\"4\"\/><text x=\"530\" y=\"120\">E\u2081<\/text><line x1=\"150\" y1=\"60\" x2=\"520\" y2=\"60\" stroke=\"#1d4ed8\" stroke-width=\"4\"\/><text x=\"530\" y=\"65\">E\u2082<\/text><path d=\"M245 178 L245 118\" stroke=\"#dc2626\" stroke-width=\"4\" marker-end=\"url(#arr)\"\/><text x=\"260\" y=\"150\" fill=\"#dc2626\">absorption<\/text><path d=\"M390 62 L390 112\" stroke=\"#16a34a\" stroke-width=\"4\" marker-end=\"url(#arr2)\"\/><text x=\"405\" y=\"92\" fill=\"#16a34a\">\u00e9mission<\/text><defs><marker id=\"arr\" markerWidth=\"10\" markerHeight=\"10\" refX=\"5\" refY=\"3\" orient=\"auto\"><path d=\"M0,0 L0,6 L6,3 z\" fill=\"#dc2626\"\/><\/marker><marker id=\"arr2\" markerWidth=\"10\" markerHeight=\"10\" refX=\"5\" refY=\"3\" orient=\"auto\"><path d=\"M0,0 L0,6 L6,3 z\" fill=\"#16a34a\"\/><\/marker><\/defs><\/svg><\/div><div class=\"formula\">|\u0394E| = (h \u00d7 c) \/ \u03bb donc \u03bb = (h \u00d7 c) \/ |\u0394E|<\/div><p class=\"danger\"><b>Erreur classique :<\/b> si \u0394E est donn\u00e9 en eV, on convertit en joules avant d\u2019utiliser E = hc \/ \u03bb.<\/p><\/div>\n<div class=\"card third\"><h2>Absorption<\/h2><p>Un atome absorbe un photon si l\u2019\u00e9nergie du photon correspond exactement \u00e0 l\u2019\u00e9cart entre deux niveaux.<\/p><p>\u00c9lectron : niveau bas \u2192 niveau haut.<\/p><\/div><div class=\"card third\"><h2>\u00c9mission<\/h2><p>Un atome excit\u00e9 revient vers un niveau plus bas en \u00e9mettant un photon.<\/p><p>\u00c9lectron : niveau haut \u2192 niveau bas.<\/p><\/div><div class=\"card third\"><h2>Spectres<\/h2><p>Chaque atome poss\u00e8de ses propres raies. Le spectre de raies permet donc d\u2019identifier un \u00e9l\u00e9ment chimique.<\/p><\/div>\n<div class=\"card\"><h2>4. Exemple-type complet<\/h2><p>Un atome poss\u00e8de E<sub>0<\/sub> = \u221213,6 eV et E<sub>1<\/sub> = \u221211,5 eV. On cherche la longueur d\u2019onde absorb\u00e9e lors de la transition E<sub>0<\/sub> \nightarrow E_1.<\/p><div class=\"formula\">\u0394E = E<sub>1<\/sub> \u2212 E<sub>0<\/sub> = \u221211,5 \u2212 (\u221213,6) = 2,1 eV<\/div><div class=\"formula\">\u0394E = 2,1 \u00d7 1,60 \u00d7 10<sup>\u221219<\/sup> = 3,36 \u00d7 10<sup>\u221219<\/sup> J<\/div><div class=\"formula\">\u03bb = (6,63 \u00d7 10<sup>\u221234<\/sup> \u00d7 3,00 \u00d7 10<sup>8<\/sup>) \/ (3,36 \u00d7 10<sup>\u221219<\/sup>) = 5,92 \u00d7 10<sup>\u22127<\/sup> m = 592 nm<\/div><\/div>\n<div class=\"card exo\"><h2>Exercice int\u00e9gr\u00e9 niveau bac<\/h2><p>Un atome inconnu a pour niveau fondamental E<sub>0<\/sub> = \u221211,5 eV. Il absorbe des radiations de longueurs d\u2019onde 410 nm et 520 nm correspondant aux transitions E<sub>1<\/sub> \u2212 E<sub>0<\/sub> et E<sub>2<\/sub> \u2212 E<sub>0<\/sub>.<\/p><ol><li>Calculer \u0394E<sub>1<\/sub> en eV puis E<sub>1<\/sub>.<\/li><li>Calculer \u0394E<sub>2<\/sub> en eV puis E<sub>2<\/sub>.<\/li><li>Construire le d\u00e9but du diagramme d\u2019\u00e9nergie.<\/li><li>Expliquer pourquoi l\u2019observation de ces raies peut identifier l\u2019atome.<\/li><\/ol><\/div>\n<div class=\"card\"><h2>5. Mini quiz<\/h2><div class=\"quiz\"><details><summary>Pourquoi la lumi\u00e8re violette est-elle plus \u00e9nerg\u00e9tique que la lumi\u00e8re rouge ?<\/summary><p>Parce que sa longueur d\u2019onde est plus petite, donc sa fr\u00e9quence est plus grande, et E = h \u00d7 f.<\/p><\/details><details><summary>Quelle condition permet l\u2019absorption d\u2019un photon par un atome ?<\/summary><p>L\u2019\u00e9nergie du photon doit \u00eatre \u00e9gale \u00e0 l\u2019\u00e9cart entre deux niveaux d\u2019\u00e9nergie de l\u2019atome.<\/p><\/details><details><summary>Quelle est la diff\u00e9rence entre spectre continu et spectre de raies ?<\/summary><p>Un spectre continu contient toutes les longueurs d\u2019onde d\u2019un domaine ; un spectre de raies contient seulement certaines longueurs d\u2019onde pr\u00e9cises.<\/p><\/details><details><summary>Pourquoi une raie d\u2019absorption est-elle sombre ?<\/summary><p>Parce qu\u2019une radiation pr\u00e9cise a \u00e9t\u00e9 absorb\u00e9e par les atomes travers\u00e9s.<\/p><\/details><\/div><\/div>\n<\/section><\/div><script>\nfunction speakCourse(){stopSpeak();const text=document.getElementById('courseText').innerText;const u=new SpeechSynthesisUtterance(text);u.lang='fr-FR';u.rate=.92;window.speechSynthesis.speak(u)}function stopSpeak(){window.speechSynthesis.cancel()}\n<\/script><\/body><\/html>\n","protected":false},"excerpt":{"rendered":"<p>CH7 – Mod\u00e8le ondulatoire et particulaire de la lumi\u00e8re CH7 – Mod\u00e8le ondulatoire et particulaire de la lumi\u00e8re Cours complet de premi\u00e8re sp\u00e9cialit\u00e9 : longueur d\u2019onde,...<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-850","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/pages\/850","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/comments?post=850"}],"version-history":[{"count":2,"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/pages\/850\/revisions"}],"predecessor-version":[{"id":856,"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/pages\/850\/revisions\/856"}],"wp:attachment":[{"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/media?parent=850"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

{"id":850,"date":"2026-05-28T14:28:40","date_gmt":"2026-05-28T12:28:40","guid":{"rendered":"https:\/\/pcwallis.malo.wf\/?page_id=850"},"modified":"2026-05-28T23:00:28","modified_gmt":"2026-05-28T21:00:28","slug":"modele-ondulatoire-et-corpusculaire-de-la-lumiere","status":"publish","type":"page","link":"https:\/\/pcwallis.malo.wf\/index.php\/modele-ondulatoire-et-corpusculaire-de-la-lumiere\/","title":{"rendered":"modele ondulatoire et corpusculaire de la lumi\u00e8re"},"content":{"rendered":"\n\n\nCH7 – Mod\u00e8le ondulatoire et particulaire de la lumi\u00e8re<\/title>\n<style>\n:root{--bg:#f6f7fb;--ink:#111827;--muted:#4b5563;--accent:#7c3aed;--accent2:#0ea5e9;--card:#fff;--border:#e5e7eb;}\n*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;background:var(--bg);color:var(--ink);line-height:1.55}.wrap{max-width:1120px;margin:auto;padding:22px}header{background:linear-gradient(135deg,#312e81,#0891b2);color:white;border-radius:24px;padding:28px;box-shadow:0 16px 35px #0002}h1{margin:0;font-size:clamp(1.7rem,4vw,3.1rem)}.subtitle{font-size:1.1rem;opacity:.95;max-width:900px}.toolbar{display:flex;gap:12px;flex-wrap:wrap;margin-top:18px}.btn{display:inline-flex;align-items:center;gap:8px;background:#fff;color:#111827;text-decoration:none;border-radius:999px;padding:10px 15px;font-weight:700;border:1px solid #ffffff55;cursor:pointer}.btn.dark{background:#111827;color:white}.grid{display:grid;grid-template-columns:repeat(12,1fr);gap:16px;margin-top:18px}.card{grid-column:span 12;background:var(--card);border:1px solid var(--border);border-radius:22px;padding:20px;box-shadow:0 10px 28px #0000000d}@media(min-width:820px){.half{grid-column:span 6}.third{grid-column:span 4}.two{grid-column:span 8}}h2{margin-top:0;color:#312e81}h3{color:#0f172a}.formula{background:#f3f4f6;border:1px solid #c7d2fe;border-left:6px solid var(--accent);padding:14px;border-radius:14px;font-size:1.12rem;text-align:center;margin:12px 0}.memo{background:#fff7ed;border-left:6px solid #f97316}.exo{background:#f8fafc;border-left:6px solid #0ea5e9}.danger{background:#fef2f2;border-left:6px solid #ef4444}.ok{background:#ecfdf5;border-left:6px solid #10b981}table{border-collapse:collapse;width:100%;font-size:.95rem}td,th{border:1px solid #d1d5db;padding:8px;vertical-align:top}th{background:#eef2ff}.spectrum{height:80px;border-radius:16px;background:linear-gradient(90deg,#111 0 8%,#312e81 10%,#4f46e5 18%,#0ea5e9 30%,#22c55e 42%,#fde047 55%,#f97316 67%,#ef4444 78%,#111 90%);position:relative;margin:16px 0}.spectrum span{position:absolute;bottom:-26px;font-size:.85rem}.svgbox{width:100%;overflow:auto;text-align:center}svg{max-width:100%;height:auto}.quiz details{border:1px solid #ddd;border-radius:12px;margin:8px 0;padding:10px;background:white}.small{font-size:.9rem;color:var(--muted)}@media print{.toolbar,.no-print{display:none}body{background:white}.card,header{box-shadow:none}}\n<\/style><\/head><body><div class=\"wrap\">\n<header><h1>CH7 – Mod\u00e8le ondulatoire et particulaire de la lumi\u00e8re<\/h1><p class=\"subtitle\">Cours complet de premi\u00e8re sp\u00e9cialit\u00e9 : longueur d\u2019onde, photon, \u00e9nergie, absorption, \u00e9mission, niveaux d\u2019\u00e9nergie et spectres de raies.<\/p><div class=\"toolbar\"><button class=\"btn\" onclick=\"speakCourse()\">\ud83d\udd0a \u00c9couter le cours<\/button><button class=\"btn dark\" onclick=\"stopSpeak()\">Stop audio<\/button><a class=\"btn\" href=\"https:\/\/pcwallis.malo.wf\/wp-content\/uploads\/2026\/05\/chapitre_modele_lumiere_premiere_v1_cours_imprimable.pdf\" target=\"_blank\">\ud83d\udcc4 PDF cours imprimable<\/a><a class=\"btn\" href=\"https:\/\/pcwallis.malo.wf\/wp-content\/uploads\/2026\/05\/chapitre_modele_lumiere_premiere_v1_exercices_types.pdf\" target=\"_blank\">\ud83e\uddea PDF exercices types<\/a><\/div><\/header>\n<section class=\"grid\" id=\"courseText\">\n<div class=\"card memo\"><h2>\u00c0 retenir en 30 secondes<\/h2><p>La lumi\u00e8re peut \u00eatre d\u00e9crite comme une <b>onde<\/b>, avec une fr\u00e9quence f et une longueur d\u2019onde \u03bb, mais aussi comme un flux de <b>photons<\/b>. Chaque photon transporte une \u00e9nergie. Un atome absorbe ou \u00e9met seulement certaines \u00e9nergies : cela cr\u00e9e des <b>raies spectrales<\/b>, v\u00e9ritables signatures des \u00e9l\u00e9ments chimiques.<\/p><\/div>\n<div class=\"card half\"><h2>1. Mod\u00e8le ondulatoire<\/h2><p>La lumi\u00e8re est une onde \u00e9lectromagn\u00e9tique. Dans le vide ou dans l\u2019air, elle se propage \u00e0 la c\u00e9l\u00e9rit\u00e9 :<\/p><div class=\"formula\">c = 3,00 \u00d7 10<sup>8<\/sup> m\u00b7s<sup>\u22121<\/sup><\/div><div class=\"formula\">\u03bb = c \/ f<\/div><p>Avec \u03bb en m, c en m\u00b7s\u207b\u00b9 et f en Hz.<\/p><div class=\"spectrum\"><span style=\"left:18%\">UV<\/span><span style=\"left:37%\">Visible<\/span><span style=\"left:70%\">IR<\/span><\/div><p class=\"small\">Visible : environ 400 nm \u00e0 800 nm. Plus \u03bb est petite, plus la fr\u00e9quence et l\u2019\u00e9nergie sont grandes.<\/p><\/div>\n<div class=\"card half\"><h2>2. Mod\u00e8le particulaire : le photon<\/h2><p>Un photon est un paquet d\u2019\u00e9nergie transport\u00e9 par la lumi\u00e8re.<\/p><div class=\"formula\">E = h \u00d7 f et E = (h \u00d7 c) \/ \u03bb<\/div><p>Constante de Planck :<\/p><div class=\"formula\">h = 6,63 \u00d7 10<sup>\u221234<\/sup> J\u00b7s<\/div><p>Conversion utile :<\/p><div class=\"formula\">1 eV = 1,60 \u00d7 10<sup>\u221219<\/sup> J<\/div><\/div>\n<div class=\"card two\"><h2>3. Interaction lumi\u00e8re – mati\u00e8re<\/h2><p>Dans un atome, les \u00e9lectrons occupent des niveaux d\u2019\u00e9nergie bien pr\u00e9cis. Le niveau le plus bas est l\u2019\u00e9tat fondamental E<sub>0<\/sub>. Les niveaux plus hauts sont des \u00e9tats excit\u00e9s E<sub>1<\/sub>, E<sub>2<\/sub>, etc.<\/p><div class=\"svgbox\"><svg viewBox=\"0 0 620 230\"><line x1=\"80\" y1=\"25\" x2=\"80\" y2=\"205\" stroke=\"#111\"\/><text x=\"48\" y=\"35\">E<\/text><line x1=\"150\" y1=\"180\" x2=\"520\" y2=\"180\" stroke=\"#1d4ed8\" stroke-width=\"4\"\/><text x=\"530\" y=\"185\">E\u2080 \u00e9tat fondamental<\/text><line x1=\"150\" y1=\"115\" x2=\"520\" y2=\"115\" stroke=\"#1d4ed8\" stroke-width=\"4\"\/><text x=\"530\" y=\"120\">E\u2081<\/text><line x1=\"150\" y1=\"60\" x2=\"520\" y2=\"60\" stroke=\"#1d4ed8\" stroke-width=\"4\"\/><text x=\"530\" y=\"65\">E\u2082<\/text><path d=\"M245 178 L245 118\" stroke=\"#dc2626\" stroke-width=\"4\" marker-end=\"url(#arr)\"\/><text x=\"260\" y=\"150\" fill=\"#dc2626\">absorption<\/text><path d=\"M390 62 L390 112\" stroke=\"#16a34a\" stroke-width=\"4\" marker-end=\"url(#arr2)\"\/><text x=\"405\" y=\"92\" fill=\"#16a34a\">\u00e9mission<\/text><defs><marker id=\"arr\" markerWidth=\"10\" markerHeight=\"10\" refX=\"5\" refY=\"3\" orient=\"auto\"><path d=\"M0,0 L0,6 L6,3 z\" fill=\"#dc2626\"\/><\/marker><marker id=\"arr2\" markerWidth=\"10\" markerHeight=\"10\" refX=\"5\" refY=\"3\" orient=\"auto\"><path d=\"M0,0 L0,6 L6,3 z\" fill=\"#16a34a\"\/><\/marker><\/defs><\/svg><\/div><div class=\"formula\">|\u0394E| = (h \u00d7 c) \/ \u03bb donc \u03bb = (h \u00d7 c) \/ |\u0394E|<\/div><p class=\"danger\"><b>Erreur classique :<\/b> si \u0394E est donn\u00e9 en eV, on convertit en joules avant d\u2019utiliser E = hc \/ \u03bb.<\/p><\/div>\n<div class=\"card third\"><h2>Absorption<\/h2><p>Un atome absorbe un photon si l\u2019\u00e9nergie du photon correspond exactement \u00e0 l\u2019\u00e9cart entre deux niveaux.<\/p><p>\u00c9lectron : niveau bas \u2192 niveau haut.<\/p><\/div><div class=\"card third\"><h2>\u00c9mission<\/h2><p>Un atome excit\u00e9 revient vers un niveau plus bas en \u00e9mettant un photon.<\/p><p>\u00c9lectron : niveau haut \u2192 niveau bas.<\/p><\/div><div class=\"card third\"><h2>Spectres<\/h2><p>Chaque atome poss\u00e8de ses propres raies. Le spectre de raies permet donc d\u2019identifier un \u00e9l\u00e9ment chimique.<\/p><\/div>\n<div class=\"card\"><h2>4. Exemple-type complet<\/h2><p>Un atome poss\u00e8de E<sub>0<\/sub> = \u221213,6 eV et E<sub>1<\/sub> = \u221211,5 eV. On cherche la longueur d\u2019onde absorb\u00e9e lors de la transition E<sub>0<\/sub> \nightarrow E_1.<\/p><div class=\"formula\">\u0394E = E<sub>1<\/sub> \u2212 E<sub>0<\/sub> = \u221211,5 \u2212 (\u221213,6) = 2,1 eV<\/div><div class=\"formula\">\u0394E = 2,1 \u00d7 1,60 \u00d7 10<sup>\u221219<\/sup> = 3,36 \u00d7 10<sup>\u221219<\/sup> J<\/div><div class=\"formula\">\u03bb = (6,63 \u00d7 10<sup>\u221234<\/sup> \u00d7 3,00 \u00d7 10<sup>8<\/sup>) \/ (3,36 \u00d7 10<sup>\u221219<\/sup>) = 5,92 \u00d7 10<sup>\u22127<\/sup> m = 592 nm<\/div><\/div>\n<div class=\"card exo\"><h2>Exercice int\u00e9gr\u00e9 niveau bac<\/h2><p>Un atome inconnu a pour niveau fondamental E<sub>0<\/sub> = \u221211,5 eV. Il absorbe des radiations de longueurs d\u2019onde 410 nm et 520 nm correspondant aux transitions E<sub>1<\/sub> \u2212 E<sub>0<\/sub> et E<sub>2<\/sub> \u2212 E<sub>0<\/sub>.<\/p><ol><li>Calculer \u0394E<sub>1<\/sub> en eV puis E<sub>1<\/sub>.<\/li><li>Calculer \u0394E<sub>2<\/sub> en eV puis E<sub>2<\/sub>.<\/li><li>Construire le d\u00e9but du diagramme d\u2019\u00e9nergie.<\/li><li>Expliquer pourquoi l\u2019observation de ces raies peut identifier l\u2019atome.<\/li><\/ol><\/div>\n<div class=\"card\"><h2>5. Mini quiz<\/h2><div class=\"quiz\"><details><summary>Pourquoi la lumi\u00e8re violette est-elle plus \u00e9nerg\u00e9tique que la lumi\u00e8re rouge ?<\/summary><p>Parce que sa longueur d\u2019onde est plus petite, donc sa fr\u00e9quence est plus grande, et E = h \u00d7 f.<\/p><\/details><details><summary>Quelle condition permet l\u2019absorption d\u2019un photon par un atome ?<\/summary><p>L\u2019\u00e9nergie du photon doit \u00eatre \u00e9gale \u00e0 l\u2019\u00e9cart entre deux niveaux d\u2019\u00e9nergie de l\u2019atome.<\/p><\/details><details><summary>Quelle est la diff\u00e9rence entre spectre continu et spectre de raies ?<\/summary><p>Un spectre continu contient toutes les longueurs d\u2019onde d\u2019un domaine ; un spectre de raies contient seulement certaines longueurs d\u2019onde pr\u00e9cises.<\/p><\/details><details><summary>Pourquoi une raie d\u2019absorption est-elle sombre ?<\/summary><p>Parce qu\u2019une radiation pr\u00e9cise a \u00e9t\u00e9 absorb\u00e9e par les atomes travers\u00e9s.<\/p><\/details><\/div><\/div>\n<\/section><\/div><script>\nfunction speakCourse(){stopSpeak();const text=document.getElementById('courseText').innerText;const u=new SpeechSynthesisUtterance(text);u.lang='fr-FR';u.rate=.92;window.speechSynthesis.speak(u)}function stopSpeak(){window.speechSynthesis.cancel()}\n<\/script><\/body><\/html>\n","protected":false},"excerpt":{"rendered":"<p>CH7 – Mod\u00e8le ondulatoire et particulaire de la lumi\u00e8re CH7 – Mod\u00e8le ondulatoire et particulaire de la lumi\u00e8re Cours complet de premi\u00e8re sp\u00e9cialit\u00e9 : longueur d\u2019onde,...<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-850","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/pages\/850","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/comments?post=850"}],"version-history":[{"count":2,"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/pages\/850\/revisions"}],"predecessor-version":[{"id":856,"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/pages\/850\/revisions\/856"}],"wp:attachment":[{"href":"https:\/\/pcwallis.malo.wf\/index.php\/wp-json\/wp\/v2\/media?parent=850"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}