What is an Element?
You already know what matter is if you looked at my post called Matter, but what makes up matter? Matter is made up of elements. An element is a substance that cannot be broken down into anything smaller. Water is not an element because it can be broken down into hydrogen and oxygen. Since hydrogen and oxygen cannot be broken down further, they are both elements.
What are elements made of?
Elements are made up of atoms. An atom is the basic unit of an element.
What are atoms made up of?
Atoms are made up of protons(+), neutrons(neutral), and electrons(-). The protons and neutrons stick together to make the nucleus. The electrons move around the nucleus.
The number of protons in an atom is called the atomic number. Protons and Neutrons have about the same mass. This is the atomic mass unit. If you combine all the particle’s masses including the electrons, you get the atomic mass.
A molecule is a particle that have atoms joining together to make it. For example, an oxygen molecule has two oxygen atoms.
How are elements organized?
Scientists use the periodic table of elements to categorize elements. Elements are organized by atomic number. They are also grouped in metals, metalloids, and nonmetals. For more information, see my post The Periodic Table of Elements
How do we examine atoms?
Atoms are extremely small. They are too small to be examined be a regular microscope. One type of microscope scientist use is called the scanning tunneling microscope. This microscope uses a needle equivalent to the size of an atom. It moves over each atom and detects the bumps of the atoms.