This image is a model of an atom
Windows to the Universe original animation by Randy Russell.
Related links:
Elements
Atomic Nucleus
What's a molecule?
A Matter of Scale - interactive showing the sizes of things, from very tiny to huge - from NSF
Atoms
Atoms are the smallest size pieces that elements come in. Each atom has a small but heavy nucleus at its center. A cloud of tiny, fast-moving electrons orbit around the nucleus. The nucleus contains protons and neutrons. Most atoms have about as many neutrons as protons. A "normal" atom has the same number of electrons and protons.
The animation of an atom on this page is NOT to scale. In a real atom, the protons, neutrons, and electrons are very tiny compared to the distance between the nucleus and the electrons. Most of an atom is empty space. Atoms are incredibly small. They have sizes between 60 and 500 picometers (a picometer is 10-12 meters, or one trillionth of a meter!). The nucleus of an atom is about 100,000 times smaller than the whole atom. Almost all (more than 99%) of the mass of an atom is in the nucleus.
Sometimes two or more atoms "stick together" to form a molecule. Some molecules have atoms of just one type. For example, an oxygen molecule (O2) has two oxygen atoms. Other molecules combine different types of atoms. Methane (CH4) has one carbon atom and four hydrogen atoms.
You might also be interested in:
An element (also called a "chemical element") is a substance made up entirely of atoms having the same atomic number; that is, all of the atoms have the same number of protons. Hydrogen, helium, oxygen,
...more
Most things around us are made of groups of atoms connected together into packages called molecules. Molecules are made from atoms of one or more elements. Some molecules are made of only one type of
...more
Oxygen (O2) is a kind of gas. A lot of the air you breathe is oxygen. That's a good thing, since we need oxygen to stay alive! About 4/5ths of the air in Earth's atmosphere is nitrogen (N2). Almost all
...more
Methane is a kind of gas. There is a small amount of methane in the air you breathe. A methane molecule has carbon and hydrogen atoms in it. Methane is a greenhouse gas. That means it helps make Earth
...more
One way scientists measure the size of something is by its mass. Mass is sort of like weight. Scientists can even measure very, very tiny things like atoms. One measure of the size of an atom is its "atomic
...moreEvery atom has a nucleus. The nucleus has protons and neutrons in it. Scientists have a special name for the number of protons in an atom. They call it the "atomic number". There are almost 100 different
...more
Isotopes are different "versions" of an element. All atoms of an element have the same number of protons. All hydrogen atoms have one proton, all carbon atoms have 6 protons, and all uranium atoms have
...more
