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- 1. Also known as the Plum Pudding model, this model, proposed by J.J. Thomson, depicts electrons embedded in a positively charged sphere, like plums in a pudding. This model incorporated the discovery of electrons but lacked a clear understanding of the nucleus.
- 3. A molecule consisting of three atoms chemically bonded together, such as carbon dioxide (CO2).
- 4. A reaction that involves the nuclei of atoms, potentially leading to the transformation of one element into another. This concept is not explained by Dalton's Atomic Theory, which focuses on chemical reactions.
- 5. The region surrounding the nucleus of an atom where electrons are most likely to be found. It is a concept in the quantum mechanical model of the atom, which describes electrons existing in orbitals, rather than fixed paths.
- 7. Also known as the Nuclear Model, this model, proposed by Ernest Rutherford, describes a small, dense, positively charged nucleus at the center of the atom, with negatively charged electrons orbiting around it. This model was based on Rutherford's gold foil experiment and significantly advanced the understanding of atomic structure.
- 9. Elements having properties that fall between those of metals and non-metals. They often exhibit intermediate conductivity and can possess characteristics of both categories. Examples include silicon and boron.
- 10. The most current and sophisticated model of the atom, which describes electrons existing in orbitals, regions of space around the nucleus where electrons are likely to be found. It incorporates principles of quantum mechanics and provides a probabilistic description of electron behavior.
- 13. A foundational theory in chemistry proposed by John Dalton, stating that all matter is composed of indivisible atoms, atoms of a given element are identical, compounds are formed by the combination of different atoms, and chemical reactions involve the rearrangement of atoms.
- 14. A representation of the structure of an atom, developed to explain experimental observations and theoretical concepts. Various atomic models have been proposed over time, each building upon previous knowledge and addressing limitations.
- 15. A molecule consisting of two atoms chemically bonded together, such as oxygen (O2) and hydrogen (H2).
- 16. A molecule consisting of more than three atoms chemically bonded together, such as phosphorus (P4) and sulfur (S8).
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- 2. Elements that are generally poor conductors of heat and electricity, brittle, and lack metallic luster. Examples include oxygen, carbon, and sulfur.
- 6. A process that involves the rearrangement of atoms, leading to the formation of new substances with different properties. Dalton's Atomic Theory states that atoms are neither created nor destroyed in a chemical reaction, just rearranged.
- 8. Particles smaller than an atom, such as protons, neutrons, and electrons. Dalton's Atomic Theory initially considered atoms indivisible, but the discovery of these particles challenged that notion.
- 11. A model proposed by Niels Bohr that refined Rutherford's model by suggesting that electrons orbit the nucleus in specific energy levels or shells. This model helped to explain the observed line spectra of atoms.
- 12. The earliest atomic model, proposed by John Dalton, depicting the atom as a solid, indivisible sphere. This model laid the foundation for atomic theory but was later revised as scientists discovered subatomic particles and the complex nature of atoms.