Atoms, Atoms, Everywhere!

By: Hayden Langham

You Will Be Learning.......

In this brochure, you will learn about scientists who studied atoms and atoms them self!

Democritus' Atomic Ideas

Democritus, along with other scientists, used sand to understand atoms.

  • Democritus believed that there was a limit to how small a grain of sand could be divided.
  • Aristotle believed that a grain of sand could be divided indefinitely.
Democritus also was known as the laughing philosopher, because of his emphasis on cheerfulness!

Democritus believed that atoms made up all matter.

Democritus believed that when atoms collided, they repelled each other or gathered together.

People believed Aristotle over Democritus because Aristotle was more influential.

Aristotle's Elements

Aristotle was from Stagira, Greece.

Aristotle studied a very wide variety of science.

He did not believe in the atomic theory. He believed that all substances were made from fire, air, earth, and water.

Dalton's Atomic Model

Dalton's main job was teaching.

One of Dalton's experiments was investigating the presence of gases

Dalton's atomic theory had three parts:

  1. Protons
  2. Neutrons
  3. Electrons
Dalton believed atoms were the smallest part of matter, so he compared them to billiard balls.

Bohr's Atomic Model

Niels Bohr published his model of the atom in 1913

Bohr's model is useful because it explains the properties of different elements.

Bohr thought that electrons can move around the nucleus at a fixed distance.

Electrons with lower energy are closer to the nucleus.

An atom is like a ladder because you can only stand on the rungs, not in between.

Mendeleev and the Periodic Table

In the year 1869, Mendeleev developed a way to organize elements. This was the Periodic Table.

Mendeleev's main job was a scientist.

He decided to organize the elements because more and more were being discovered.

To help him work on organizing the elements he used a set of cards.

He organized the elements in order of increasing atomic mass.

Atomic mass is the mass of one atom of an element.

Mendeleev called the columns group and families.

Mendeleev called his chart the periodic table because of its repeating pattern.

The rows across in the periodic table are arranged by increasing atomic mass.

Mendeleev left spaces because those elements hadn't been discovered yet.

Why Study Atoms?

People did not believe Democritus because he couldn't experiment.

People believed Dalton because he could experiment.

We learn about Dalton's theory because he laid all the groundwork for future study of chemistry.

Dalton did not know electrons and neutrons.

Before You Click Out.....

Hopefully this taught you about atoms and scientists who studied them! Thanks for reading!