Question

Планетарная модель атома основана на опытах по

Answer 1

На опытах Резерфорда по рассеянию α - частиц атомами различных тяжелых элементов. Логика эксперимента: электроны в силу их малой массы не влияют на траекторию α-частицы. Ядра резко меняют направление движения частицы.  Хотя сама идея о схожести строения атома с солнечной системой была высказана Менделеевым ранее. Различие состоит в том, что между планетами и Солнцем действуют силы тяготения, а между положительным ядром атома и вращающимися вокруг него электронами действуют кулоновские электрические силы. Но позже оказалось, что на основе этой модели нельзя объяснить факт устойчивого существования атома. И физики продолжили исследования.

Answer 2

The Planetary Model of the Atom

The planetary model of the atom is a model that describes the structure of an atom. It was developed based on experiments conducted by scientists in the early 20th century. The model was proposed by Niels Bohr in 1913 and is also known as the Bohr model.

According to the planetary model, an atom consists of a central nucleus that contains protons and neutrons, surrounded by electrons that orbit the nucleus in specific energy levels or shells. The electrons are arranged in these energy levels based on their energy.

Key points: - The planetary model of the atom was proposed by Niels Bohr in 1913. - It describes the structure of an atom, with a central nucleus and orbiting electrons.

Structure of the Atom

In the planetary model, the nucleus is located at the center of the atom and contains protons and neutrons. Protons have a positive charge, while neutrons have no charge. The number of protons in the nucleus determines the atomic number of the atom, which defines its chemical properties.

The electrons in the planetary model are arranged in different energy levels or shells around the nucleus. Each energy level can hold a specific number of electrons. The innermost shell can hold a maximum of 2 electrons, while the second shell can hold up to 8 electrons. The subsequent shells can hold even more electrons.

Key points: - The nucleus of an atom contains protons and neutrons. - Electrons are arranged in energy levels or shells around the nucleus. - Each energy level has a maximum number of electrons it can hold.

Energy Levels and Electron Orbits

In the planetary model, electrons occupy specific energy levels or orbits around the nucleus. These energy levels are quantized, meaning that electrons can only exist in certain energy states.

The energy levels are labeled with numbers, starting from the innermost level, which is labeled as the first energy level. The energy levels farther from the nucleus have higher energy.

Electrons can move between energy levels by absorbing or emitting energy in the form of photons. When an electron absorbs energy, it moves to a higher energy level. Conversely, when an electron emits energy, it moves to a lower energy level.

Key points: - Electrons occupy specific energy levels or orbits around the nucleus. - Energy levels are quantized and labeled with numbers. - Electrons can move between energy levels by absorbing or emitting energy.

Limitations of the Planetary Model

While the planetary model of the atom was a significant advancement in understanding atomic structure, it has some limitations. One major limitation is that it does not accurately describe the behavior of electrons in more complex atoms. It fails to explain phenomena such as electron-electron repulsion and the wave-like nature of electrons.

The planetary model also does not account for the concept of electron spin, which is an intrinsic property of electrons. Additionally, it does not provide a complete explanation of atomic bonding and the formation of chemical compounds.

Key points: - The planetary model has limitations in explaining the behavior of electrons in complex atoms. - It does not account for electron-electron repulsion, electron spin, and atomic bonding.

In conclusion, the planetary model of the atom, proposed by Niels Bohr in 1913, describes the structure of an atom with a central nucleus and orbiting electrons in energy levels. While it was a significant advancement, the model has limitations in explaining the behavior of electrons in complex atoms and other atomic phenomena.