The Discovery Of The Atom

John Dalton wrote the modern atomic theory, a fundamental component of that is, the mole ratios of elements in a compound will be small whole numbers.

In this experiment, you will have a chance to test the hypothesis that Ernest Rutherford used when determining the size of the nucleus. In his "gold foil experiment," Rutherford shot alpha particles at gold atoms. Once he realized that the alpha particles were hitting a concentrated positive mass, he developed the nuclear model of the atom. Next, he set out to determine the relative size of the nucleus compared to the rest of the atom. He reasoned that the smaller the nucleus, the less likely it was to be hit by an alpha particle. This led to a simple comparative ratio:

The Ancient Greeks were the firsts to speculate on the composition of matter. They thought that it was possible that individual particles made up matter.

  Then in 1661, Irish chemist Robert Boyle supported the philosophers’ theory of how chemical elements are made up of the simplest matter, backing the theory of how matter makes up all life and is the smallest living thing (Doc. 1). But a bombshell happened in 1803 when John Dalton backed up all three theories by discovering that atoms make up all matter, and chemical compounds are made of atoms (OI).

John Dalton was a British chemist born in 1766 in England to a Quaker family. His family was poor and he was homeschooled until at age 15. He and his brother ran a school. He had the biggest effect on the atom. He was the first to bring back the idea of an atom and prove it. One reason Dalton’s discovery is important is without it

Around 2,500 years ago, Democritus and his partner Leucippus were the first ones to develop the atomic theory in written history. Their theory proposed that every kind of matter was made up of tiny particles, which were named atomos, which means that it is indivisible. This meant that Democritus and Leucippus thought there were little particles of everything, but, the next breakthrough in atomic theory wasn’t made until the early 1800s with a french chemist by the name of Antoine Lavoisier, he was the one who came up with the idea of the law of the conservation of mass, which states that matter stays the same even when it changes shape or form. Then, James Dalton said that all matter was made up of atoms, which were indivisible, and unbreakable.

He stated that this was a mysterious force but never continued his research on it. Then in 460 B.C. there was a philosopher named Democritus. Democritus and his mentor Leocippus posed the question that if he broke bread into multiple pieces how many would breaks would it take until there was no more bread. He then was able to make a few theories being all matter was created of atoms and atoms are solid but not invisible. However, there was a man named Aristotle and many other philosophers who disagreed with Democritus and said matter was composed of four main elements. Earth, fire, air, and water. For example, a liquid was made of water and a stone was made of rock. Therefore, Democritus’s theory “ was rejected by Aristotle, one of the most influential philosophers of Ancient Greece; and the atomic theory was ignored for nearly 2,000 years.”(

In the 18th century, scientists were strongly influenced by theories. In 350 B.C., Aristotle believed that everything was made from fire, earth, air and water. There later was a Greek physician named Galen. He practiced about 500 years after Aristotle. Galen believed that the body had four elements which he called humors. The four

During the early 1940’s atomic science had just began to mature. Many people were exploring the powerful mystery of the atom. Two of those people were Eugene Booth and John Dunning, who, in 1941, synthesized uranium-235. Immense scientific growth followed their contribution, since it allowed for nuclear fission (Griffith). In the years following this discovery, nuclear science took a turn. Once only used as a constructive power source, atoms began being explored for their destructive power. In 1942 the United States government funded the Manhattan Project that sole goal was to develop a nuclear bomb. The initiator for this endeavor was surprisingly the famous scientist Albert Einstein. He wrote to Franklin D. Roosevelt , and tipped him off

Within the last hundred years, the atomic model gone through dramatic changes allowing to apply the knowledge of matter understanding at atomic level into different industries like medicine such as MRI and X-Ray. This knowledge allowed doctors to treat, diagnose and certainly save millions of people throughout the years, which could not have been done without research being done on the structure of the atom funded continuously for these scientists to find more application which benefit people and comprehend the world we live in on an atomic level.

Democritus made the atomic theory widely known, which stated that the universe is composed of two elements: the atoms and the void in which these atoms exist and move. (More, 1646)

Democritus, an Ancient Greek philosopher, is widely considered to be the founding father of the Atomic Theory. Democritus proposed that matter is composed of atoms, which move through empty space. He also proposed that atoms are solid, homogeneous, indestructible, and indivisible, and that different types of atoms have different kinds of sizes and shapes, which determine the properties of matter. Democritus and other Greek philosophers Leucippus and Epicurus, were among the first to propose the size, shape, and connectivity of atoms. Democritus theorized that iron atoms are solid with hooks (which locked them in place with each other, therefore creating a solid), water ‘atoms’ are smooth and slippery, (which caused them to be in a liquid state),

Before really discussing what atoms were, why they are important, and so on. We began talking about the scientists that contributed to the study of atoms. The main scientist that we discussed were Democritus, Rutherford, Thomson, Bohr, Dalton, Heisenberg, and Chadwick. Prior to taking chemistry I only knew about Democritus, the Greek philosopher who developed the modern atomic model, and Dalton, who further developed Democritus’s model of the atomic model, but I wanted to know more about the other scientist. That night I went home and did research on the other scientist. This led me to finding out very interesting information on the other scientist and having a deeper understanding on what part of their research is still relevant today. The extra research I did on the scientist was a just a small scale example of talking my education into my own hands and getting a deeper understanding of particular

An Atom is the the basic building block of all matter. Atoms are made up of Particles, called: Protons, neutrons and Electrons. Protons carry a positive charge, the neutron carry 's a neutral charge and the electron carry’s a negative charge. The Atom has two main parts the Nucleus and the Electron Shell. The Nucleus contains the Protons and Neutrons. The electron Shell Contains the The electrons.

The most important properties of atomic and molecular structure may be exemplified using a simplified picture of an atom that is called the Bohr Model. This model was proposed by Niels Bohr in 1915; it is not completely correct, but it has many features that are approximately correct and it is sufficient for much of our discussion. The correct theory of the atom is called quantum mechanics; the Bohr Model is an approximation to quantum mechanics that has the virtue of being much simpler.