Name: atomic orbitals and quantum numbers
Uploaded: 2023-04-30T18:28:31.000Z
Duration: 2 min 28 s
Channel: JoVE

K12 Standards

Louisiana Student Standards for Science

High School

Chemistry

Matter And Its Interactions

HS-PS1-1

Electronic Structure of Atoms

Атом состоит из трех субатомных частиц – электронов, протонов и нейтронов. Положительно заряженные протоны и электрически нейтральные нейтроны образуют атомное ядро, в котором находится весь положительный заряд и большая часть массы атома.
Электроны — это отрицательно заряженные составляющие с малой массой, расположенные в пустом пространстве вокруг ядра. Атом является электрически нейтральным, когда в нем столько электронов, сколько протонов.
Электроны имеют двойственную природу — частицу и волну. Их расположение в пространстве и энергия являются взаимодополняющими свойствами. Следовательно, для электрона с четко определенной энергией его положение неопределенно.
Квантовомеханическая модель атома предсказывает, что вероятность нахождения электрона заданной энергии в трехмерной области пространства может быть определена из квадрата волновой функции, выражающей волновую природу электрона, также называемой плотностью вероятности электронов.
Функция, описывающая вероятное пространственное положение электрона определенной энергии в атоме, называется атомной орбиталью.
Каждая орбиталь соответствует уникальной комбинации трех квантовых чисел. Главное квантовое число, n, группирует орбитали в энергетические уровни или оболочки.
Угловой момент, или азимутальное квантовое число l, группирует орбитали внутри оболочек в подоболочки. Каждое значение l соответствует орбитали s, p, d или f различной формы.
Некоторые орбитальные формы могут иметь несколько возможных ориентаций, каждая из которых связана с магнитным квантовым числом ml. Количество ориентаций для данной подоболочки равно двум-l плюс одному.
Четвертое квантовое число — спиновое квантовое число, ms — связано с электронами, занимающими орбиталь, и имеет только два возможных значения: «плюс половина» и «минус одна половина». Это гарантирует, что никакие два электрона в атоме не будут иметь одинаковых значений для всех четырех квантовых чисел.
Наложение орбиталей друг на друга создает примерно сферическую форму, похожую на «облако» электронов, окружающих ядро. Вот почему атомы обычно представляют в виде сфер.

Электронная структура атомов

Атом состоит из протонов и нейтронов, которые содержатся внутри плотного образования в центре, называемого ядром, а электроны расположены вокруг ядра. Принимая во внимание корпускулярно-волновой дуализм электронов и неопределенность их положения вокруг ядра, квантовая механика обеспечивает более точную модель атомной структуры. Она описывает атомные орбитали как области вокруг ядра, где существуют электроны дискретной энергии, характеризующиеся четырьмя квантовыми числами: 

n, l, ml, и ms.

Квантово-механическая модель

Атом состоит из небольшого положительно заряженного ядра, окруженного электронами. Ядро содержит протоны и нейтроны. Протоны имеют заряд +1 и массу 1,0073 а.е.м. Нейтроны имеют нулевой заряд и массу 1,0087 а.е.м. Электроны имеют заряд −1 и массу 0,00055 а.е.м. Число протонов в ядре называется атомным номером (Z) и определяет принадлежность атома определённому элементу. Сумма чисел протонов и нейтронов в ядре называется массовым числом и, выраженная в а.е.м., приблизительно равна массе атома. Атом нейтрален, если он содержит равное количество электронов и протонов.

Были предложены различные модели для описания атомной структуры, объясняющие распределение электронов вокруг ядра. Соотношение де Бройля количественно показало, что электроны обладают свойствами как частицы, так и волны. Давая количественную оценку этому корпускулярно-волновому дуализму, Гейзенберг сформулировал принцип неопределенности: положение (связанное с природой частицы) и скорость или энергия (связанная с волновой природой) электрона не могут быть одновременно точно определены. Квантово-механическая модель дает более точное представление об атомной структуре. Она описывает трехмерное положение электрона с определенной энергией, содержащегося в атоме, в терминах вероятности, через квадрат волновой функции ψ^2. Атомные волновые функции, или атомные орбитали, описывают области атома, где с наибольшей вероятностью могут находиться электроны.

Атомная орбиталь характеризуется тремя квантовыми числами. Главное квантовое число n группирует орбитали по расположению энергетического уровня или «оболочки». Угловой момент или азимутальное квантовое число l группирует орбитали в зависимости от их формы в «подоболочки». Он имеет целые значения от 0 до n – 1 и обозначается буквами: s (l = 0), p (l = 1), d (l = 2), f (l = 3), g (l = 4), и h (l = 5). Магнитное квантовое число ml с 2l + 1 значениями в диапазоне от –l до +l описывает ориентацию орбитали в пространстве. Кроме того, каждый электрон имеет спиновое квантовое число ms, которое может быть равно ±1/2. Никакие два электрона в одном и том же атоме не могут иметь одинаковый набор значений всех четырех квантовых чисел.


Атом состоит из протонов и нейтронов, которые содержатся внутри плотного центрального ядра, называемого ядром, с электронами, присутствующими вокруг ...

Education

JoVE Core

Organic Chemistry

Органическая химия

Unit 1

Раздел 1

Covalent Bonding and Structure

Ковалентная связь и структура

KEY TERMS AND CONCEPTS

ОСНОВНЫЕ ТЕРМИНЫ И ПОНЯТИЯ

atomic orbitals and quantum numbers

Atomic orbitals and quantum numbers describe how electrons are arranged around the nucleus. An atom has a small, positively charged nucleus with electrons surrounding it. The nucleus contains protons and neutrons, and the quantum mechanical model gives a better picture of this structure than older models.

Protons carry a +1 charge and have a mass of 1.0073 amu. Neutrons have no charge and have a mass of 1.0087 amu. Electrons carry a −1 charge and have a mass of 0.00055 amu. The number of protons is the atomic number, Z, and it defines the element. The total number of protons and neutrons is the mass number, and it is approximately equal to the atom’s mass in amu. An atom is neutral when it has equal numbers of protons and electrons.

The quantum model grew from ideas about electron behavior. The de Broglie relation showed that electrons act like both particles and waves. Heisenberg’s uncertainty principle added that an electron’s position and its velocity or energy cannot both be known with full precision at the same time. Because of this, electron location is described in a probabilistic way using the square of the wavefunction, ψ².

Atomic wavefunctions, or atomic orbitals, show the regions where electrons are most likely to be found. Orbitals are described by four quantum numbers. The principal quantum number, n, gives the energy level or shell. The angular momentum, or azimuthal, quantum number, l, describes orbital shape and forms subshells. Its values run from 0 to n − 1, and the labels are s, p, d, f, g, and h for l = 0 through 5.

The magnetic quantum number, ml, describes how an orbital is oriented in space. It has 2l + 1 possible values, ranging from −l to +l. The spin quantum number, ms, can be +1/2 or −1/2. No two electrons in the same atom can have the same set of values for all four quantum numbers.

Atomic Orbitals and Quantum Numbers

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electronic structure of atoms

Atomic orbitals and quantum numbers describe how electrons are arranged around the nucleus. An atom has a small, positively charged nucleus with electrons surrounding it. The nucleus contains protons and neutrons, and the quantum mechanical model gives a better picture of this structure than older models. Protons carry a +1 charge and have a mass of 1.0073 amu. Neutrons have no charge and have a mass of 1.0087 amu. Electrons carry a −1 charge and have a mass of 0.00055 amu. The number of...

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chemical bonds

Chemical Bonds: Types and Strength

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Resonance in Nitrite and Carbonate Ions

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intermolecular forces and physical properties

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Why Some Substances Dissolve in Water

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Functional Groups and Organic Molecules

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HS-PS1-2

HS-PS1-3

motion-and-stability-forces-and-interactions

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HS-PS2-6

Virginia  Standards of Learning

HIgh School

CH.2

CH.2.d

Next Generation Science Standards

Physical Science

Matter and Its Interactions

Florida Department of Education

SC.912.P.8

SC.912.P.8.5

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

C-PS1-1

C-PS1-3.

Motion and Stability: Forces and Interactions

C-PS2-6.

Physics

P-PS2-6.

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HS-PS1-4

Atomic Orbitals and Quantum Numbers

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