Properties of Matter Help
Chemistry is defined as the study of matter and the way it reacts in different situations. But, what is matter?
At first, people thought matter only included things that could be seen and measured, like salt, grain, and olive oil. Everyone used their senses to define what they saw, heard, tasted, touched, and smelled. Anything that could not be sensed simply did not exist or belonged in the realm of myths and legends. Most people only believed in what they saw for themselves. They doubted everything until they had experienced it for themselves, usually by seeing it “with their own eyes.”
With the beginning of the scientific era, the search for exactly what makes up the “stuff” of the universe became more intense.
Matter is defined as anything that has mass and occupies space.
We now know that even in the unseen world matter exists that is too small to be seen or measured except with very complex machines and sometimes not even then. Sometimes all scientists can do is observe the effects of matter, even though the actual matter cannot be obtained.
Around 495 , a Greek philosopher named Democritus wondered if substances could be divided into smaller and smaller parts indefinitely. He thought that eventually particles would be reached that could no longer be divided. He called these smallest particles atoms (from the Greek word atomos , which means “not divided”). The great philosophers Aristotle and Plato thought matter was continuous, fluid, and could not be divided into individual particles.
In 100 , another forward thinker named Lucretius wrote a long, descriptive poem called De Rerum Natura (The Nature of Things), praising early ideas that leaned toward an atomic theory of matter. Since few people could read and most gained information through story telling, the poem helped people to understand the basic nature of matter. The invention of the Gutenberg printing press in 1452, which used olive oil ink with a screw-type wine press, helped to spread the knowledge of the time.
The De Rerum Natura poem was one of the first texts set in print. This fact helped the atomic theory survive. Along with religious texts and Bibles of the time, the poem was one of the few things available to read.
Once the first seeds of the atomic theory spread, scientists began thinking about matter in particle form. Experiments were performed and measurements taken to discover how compounds could be further divided, rearranged, and combined.
In the late 1700s, Antoine Lavoisier, the father of modern chemistry, insisted on precise measurements to better compare results and explain the properties of matter. Unfortunately, though a brilliant scientist, he was also associated with French taxation and the ruling governmental class. In 1794, his research was cut short by the guillotine and the French Revolution.
Since then, modern scientists have discovered particles that are smaller than an atom. These subatomic particles, which exist in the core of an atom, are called protons with a positive charge, and neutrons which are neutral and have no charge. Electrons orbit the nucleus like untamed satellites that are attracted by the forces of electromagnetism.
Figure 3.1 shows how the core of an atom might look if a model were made of the subatomic particles.
In 1968, quarks were discovered. Quarks are particles of matter that are constituents of neutrons and protons. So far, six different types of quarks have been identified. These will be discussed more in later chapters.