What Is an Atom?
The building blocks of matter are called atoms. Yet you may be wondering what, exactly, is an atom? Here's a look at what an atom is and some examples of atoms.
Basic Model of the Atom
Are you confused about atoms, elements, protons, neutrons, electrons, isotopes, and ions? Here's a basic look at the model of the atom. It's a great overview for kids or anyone looking to grasp the essentials of atomic theory.
Atoms and Atomic Theory - Study Guide
Get essential facts about atoms and the basics of atomic theory, work problems to test your skills, then take a quiz to make sure you understand the concepts.
This is a collection of diagrams of atoms, showing the numbers of protons, neutrons, and electrons present in the atom or isotope of an element.
Atom Basics Quiz
Do you understand the basic concepts of atomic theory? Do you have your protons, electrons, and neutrons all sorted out? Here's a ten question multiple choice quiz to test your knowledge.
How Do I Make a Model of an Atom?
Atoms are the smallest units of each element and the building blocks of matter. Here's how to make a model of an atom.
Atomic Structure Quiz
This ten question multiple choice quiz tests your comprehension of the electric nature of atoms, components of atomic structure, oxidation numbers, valence, quantum numbers, electron configuration, and Lewis dot structures.
Atomic Structure & Periodic Table Quiz
Test your understanding of atomic structure and the periodic table with this 10-question multiple choice quiz. Use the atomic structure and periodic table quiz to help yourself study for the AP chemistry exam or a first year college chemistry test.
Bohr Model of the Atom
The Bohr Model has an atom consisting of a small, positively-charged nucleus orbited by negatively-charged electrons. Here's a closer look at the Bohr Model, which is sometimes called the Rutherford-Bohr Model.
Ions, Isotopes, Atoms Quiz
If you're given the nuclear symbol for an element, can you identify how many protons and neutrons it has? If you see an ion symbol, do you know how many electrons are present? Here's your chance to test yourself.
Relating Atomic Number to Atomic Mass - Isotopes
Higher atomic number doesn't imply higher atomic mass. At least not always! Sometimes one element of lower atomic number can have a higher atomic mass. Learn about the effect of isotopic ratios on atomic mass.
Electrons are too small to observe directly, but it's possible to determine their shape by watching how they influence chemical bonds. By observing the movement of electrons, scientists have been able to discern their shape.
What Is The Rydberg Formula?
The Rydberg formula is a mathematical formula used to predict the wavelength of light resulting from an electron moving between energy levels of an atom.
How Many Protons, Neutrons, and Electrons Are There in an Atom?
Follow these simple steps to find the number of protons, neutrons, and electrons for an atom of any element.
Why Do Protons and Neutrons Stick Together?
Protons repel each other because of their electrical charge, yet stick together with neutrons in the atomic nucleus. Here's the explanation for why that happens and the forces that hold atoms together.