Question

1.How does the description of electrons from General Chemistry compare to that presented here?

2.What is your reaction to the first paragraph of “A Break with the Past” (pg 91 on pdf)? Should we stop including pictures when describing subatomic particles? i dont have the pdf of the book. Can somebody help please

Answer 1

1. An atom is present at the most basic level in everything we see around us. In fact, every living organism is composed of atoms. Every non-living thing around you such as tables, chairs, water, etc is made up of matter. But the building blocks of matter are atoms. Therefore, living or non-living, everything is composed of atoms. Let us take a look at the structure of atom.

Atom is a Greek word which means “indivisible.” The Greeks believed that matter can be broken down into very small invisible particles called atoms. Greek philosophers such as Democritus and John Dalton put forward the concept of the atom. Democritus explained the nature of matter. He also proposed that all substances are made up of matter. He stated atoms are constantly moving, invisible, minuscule particles that are different in shape, size, temperature and cannot be destroyed.

Later in the year 1808, John Dalton proposed the atomic theory and explained the law of chemical
combination. By the end of 18th and the early 20th centuries, many scientists such as J.J Thomson,
Gold stein, Rutherford, Bohr among others developed and proposed several concepts on “atom.”

Atom is the smallest unit of matter that is composed of a positively charged center termed as “nucleus” and the central nucleus is surrounded by negatively charged electrons. Even though an atom is the smallest unit of matter but it retains all the chemical properties of an element. For example, a silver spoon is made up of silver atoms with few other constituents. A silver atom obtains its properties from tiny subatomic particles that it is composed of.

Atoms are further arranged and organized to form larger structures known as molecules. Atoms, molecules adhere to the general chemistry and physics rule even when they are part of living breathing human body. Let us study atoms and molecules to further understand how the atoms react, behave and interact in cells form an essential part of living and nonliving world.