History Of The Atom- Mrs. A. Wilson- Grade 8

Protons are subatomic particles that carry a positive charge. They are found in the nucleus of an atom along with neutrons, which are neutral in charge. Electrons, on the other hand, are negatively charged particles that orbit around the nucleus. Mesons are also subatomic particles, but they can carry either a positive or negative charge. Therefore, the correct answer is proton, as it is the only subatomic particle mentioned that is positively charged.

Thomson concluded that electrons were present in all atoms. This conclusion was based on his experiments with cathode rays, where he observed that these rays were made up of negatively charged particles. He proposed the "plum pudding" model of the atom, suggesting that atoms were composed of a positively charged "pudding" with embedded electrons. This discovery revolutionized our understanding of atomic structure and paved the way for further advancements in the field of physics.

Electrons are negatively charged particles of the atom. They are found outside the nucleus and orbit around it in energy levels. Electrons play a crucial role in determining the chemical and physical properties of an element, as they are involved in chemical bonding and electrical conductivity. Unlike protons and neutrons, which are found in the nucleus and carry positive and neutral charges respectively, electrons carry a negative charge.

Electrons in the cloud, referring to the electron cloud or electron cloud model, do indeed absorb and release energy. This is a fundamental concept in quantum mechanics, where electrons can move to higher energy levels by absorbing energy and then return to lower energy levels by releasing energy in the form of photons. This behavior is responsible for various phenomena such as the emission and absorption of light, as well as the behavior of electrons in chemical reactions and electronic devices.

This order represents the chronological progression of scientists who proposed theories of the atom from the 1800s to the present. Dalton was the first to propose a modern atomic theory in the early 1800s. Thomson then discovered the electron in the late 1800s, followed by Rutherford's discovery of the nucleus in the early 1900s. Bohr expanded on Rutherford's model by proposing energy levels and orbits for electrons in the atom. Finally, the electron cloud model, which describes the probability of finding electrons in certain regions around the nucleus, was developed later.

J.J. Thomson's atomic model was compared to a Plum Pudding because it proposed that atoms were made up of a positively charged "pudding" with negatively charged electrons embedded in it, similar to the way raisins are embedded in a plum pudding. This model suggested that the positive and negative charges were evenly distributed throughout the atom, creating a neutral overall charge. However, later experiments and discoveries led to the development of the more accurate planetary model of the atom.

J. J. Thomson is credited with discovering the electron. In 1897, he conducted experiments using cathode rays and observed that they were composed of negatively charged particles. He proposed that these particles were fundamental units of electricity, which he called "corpuscles" but later became known as electrons. Thomson's discovery of the electron revolutionized our understanding of atomic structure and laid the foundation for the development of modern physics.

Protons and neutrons are the two particles found to be located in the nucleus. The nucleus is the central part of an atom, and it contains most of the atom's mass. Protons have a positive charge, while neutrons have no charge. These particles are tightly packed together in the nucleus, while electrons, which have a negative charge, orbit around the nucleus in electron shells. The discovery of protons and neutrons in the nucleus was a significant advancement in understanding the structure of atoms.

Niels Bohr proposed an atomic model in which electrons move around the nucleus in orbits arranged in energy shells. This model, known as the Bohr model, was a significant advancement in our understanding of the atom. It explained the stability of atoms by suggesting that electrons occupy specific energy levels or shells, and that they can jump between these shells by absorbing or emitting energy. This model laid the foundation for further developments in quantum mechanics and atomic theory.

The graphic represents the Electron Cloud Model. This model suggests that electrons do not orbit the nucleus in fixed paths, but rather exist in a "cloud" or probability distribution around the nucleus. This model takes into account the wave-like nature of electrons and provides a more accurate representation of their behavior within an atom.

This graphic illustrates the model proposed by John Dalton. Dalton was an English chemist who proposed the atomic theory, which states that all matter is made up of indivisible particles called atoms. He believed that atoms were solid, indivisible spheres with no internal structure. This model is often referred to as the "billiard ball" model, as it compares atoms to small, solid balls.

The proper interpretation of this Atomic Model is that electrons are scattered throughout the atom. This means that electrons are not confined to the nucleus or the edges of the atom, but rather exist in various energy levels or orbitals around the nucleus. This model is known as the electron cloud model, which suggests that electrons occupy regions of space around the nucleus called orbitals. It is important to note that protons are also located in the nucleus, but the question specifically mentions electrons.

Ernest Rutherford is credited with discovering the nucleus. Through his gold foil experiment, Rutherford observed that some alpha particles were deflected at large angles, suggesting the presence of a concentrated positive charge in the center of an atom. He proposed that this positive charge, which he called the nucleus, is surrounded by negatively charged electrons in a cloud-like structure. This groundbreaking discovery revolutionized our understanding of atomic structure and laid the foundation for further advancements in the field of nuclear physics.

Dalton's theory of the atom states that atoms are indivisible and indestructible, meaning they cannot be divided or destroyed. Therefore, the statement "He said that atoms are divisible and destructible" contradicts Dalton's theory and is not one of the ideas based on his theory.

This illustration represents the model proposed by Ernest Rutherford. Rutherford is known for his gold foil experiment, which led to the discovery of the atomic nucleus and the concept of a mostly empty space within atoms. His model suggested that the atom consists of a small, dense, and positively charged nucleus at the center, with electrons orbiting around it. This model played a significant role in advancing our understanding of atomic structure.

The correct answer is the Electron Cloud Model. This model, also known as the Quantum Mechanical Model, describes electrons as existing in a cloud-like region around the nucleus rather than in fixed orbits. It acknowledges that electrons have different energy levels and can transition between them, similar to the Bohr model. This model is based on the principles of quantum mechanics and provides a more accurate representation of the behavior of electrons in an atom.

James Chadwick is the correct answer because he was the scientist who discovered the neutron. In 1932, Chadwick conducted experiments that led to the discovery of the neutron, a subatomic particle with no charge found in the nucleus of an atom. This discovery was crucial for understanding atomic structure and the development of nuclear physics. Chadwick's work earned him the Nobel Prize in Physics in 1935.

John Dalton is known as the "Father of Modern Chemistry" because of his groundbreaking work in the field of atomic theory. Dalton proposed that all matter is made up of tiny indivisible particles called atoms, each with their own unique properties. This theory laid the foundation for modern chemistry and our understanding of the composition and behavior of matter. Dalton's work also contributed to the development of the periodic table and the concept of chemical reactions. His contributions have had a lasting impact on the field of chemistry and earned him the title of the "Father of Modern Chemistry".

Ernest Rutherford concluded that atoms are mostly empty space through his famous gold foil experiment. In this experiment, Rutherford bombarded a thin sheet of gold foil with alpha particles and observed their deflection. He found that most of the alpha particles passed straight through the foil, suggesting that atoms have a lot of empty space. However, a small fraction of the particles were deflected at large angles, indicating the presence of a dense, positively charged nucleus within the atom. This groundbreaking experiment led to the development of the nuclear model of the atom.

Ernest Rutherford hypothesized that electrons circled the nucleus, like tiny planets in a solar system.