In 1808, whose work provided a physical picture of how compounds are formed by the combination of two or more different types of atoms?

Key Points 

• John Dalton was an English chemist, physicist, and meteorologist who is best known for his pioneering work in the development of modern atomic theory.
• Dalton's atomic theory, which he proposed in 1808, provided a physical picture of how compounds are formed by the combination of two or more different types of atoms.
• He suggested that all matter is made up of tiny, indivisible particles called atoms, which combine in fixed ratios to form compounds.
• His theory was based on several key principles, including the idea that atoms of different elements have different weights and properties, that atoms can combine to form molecules, and that chemical reactions involve the rearrangement of atoms.
• Dalton's work on atomic theory was groundbreaking and laid the foundation for modern chemistry.
• He was also the first scientist to study the behavior of gases and to develop a method for measuring the relative weights of atoms.

Additional Information

George Zweig

• He proposed the concept of quarks in 1964, which are subatomic particles that makeup protons and neutrons.
• He suggested that quarks come in six different "flavors" and that they are held together by a strong nuclear force.
• Joseph J Thomson
• He discovered the electron in 1897 while studying cathode rays.
• He proposed the plum pudding model of the atom, which suggested that atoms were made up of a positively charged substance with negatively charged electrons embedded in it.

Niels Bohr

• He developed the Bohr model of the atom in 1913, which proposed that electrons orbit the nucleus at fixed energy levels.
• He also suggested that electrons can jump between energy levels by absorbing or emitting energy in the form of photons.