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Homework Statement
How do we know that matter consist of atom?
AJ Bentley said:If I remember correctly, it was John Dalton who first proposed the existence of atoms. Read up on how he came to that conclusion. The word 'valency' comes into it.
alxm said:But valency doesn't come into Dalton's rationale
An atom is the basic unit of matter that makes up all substances. It is the smallest particle of an element that retains the properties of that element.
The concept of atoms was first proposed by ancient Greek philosophers, but it wasn't until the 19th century that scientists were able to provide evidence for their existence through experiments and observations. Today, we have advanced technologies such as electron microscopes that allow us to directly observe atoms.
There are several pieces of evidence that support the existence of atoms. One of the most compelling is the observation of Brownian motion, which is the random movement of particles in a fluid. This can only be explained by the collisions of individual atoms. Additionally, various experiments, such as the Thomson's cathode ray tube experiment and the Rutherford's gold foil experiment, have provided evidence for the existence of atoms.
No, we cannot see atoms with the naked eye as they are too small to be seen. They are on the nanoscale, which is one billionth of a meter. However, with the use of specialized instruments like electron microscopes, we can indirectly observe atoms and their behavior.
Atoms are the building blocks of matter because they are the smallest unit of an element that retains the properties of that element. When atoms combine, they form molecules, which make up all substances. This has been confirmed through various experiments and observations, supporting the idea that atoms are indeed the building blocks of matter.