Chalkboard with description of periodic table notation for oxygen.  There is a square with three values in it.  Top has atomic number, center has element symbol, and bottom has atomic mass value.  The atomic number equals number of protons and also the number of electrons in a neutral atom.  Atomic mass equals the mass of the entire atom.

Check out the blackboard. That box on the left has all of the information you need to know about one element. It tells you the mass of one atom, how many pieces are inside, and where it should be placed on the periodic table.

In the next section we're going to cover electron orbitals or electron shells. This may be a new topic to some of you.

Electrons In The Shells

Take a look at the picture below. Each of those colored balls is an electron. In an atom, the electrons spin around the center, also called the nucleus. The electrons like to be in separate shells/orbitals. Shell number one can only hold 2 electrons, shell two can hold 8, and for the first eighteen elements shell three can hold a maximum of eight electrons. As you learn about elements with more than eighteen electrons you will find that shell three can hold more than eight. Once one shell is full, the next electron that is added has to move to the next shell.

So... for the element of OXYGEN, you already know that the atomic number tells you the number of electrons. That means there are 8 electrons in an oxygen atom. Looking at the picture, you can see there are two electrons in shell one and six in shell two.


Oxygen Electron GraphicOxygen Orbital Graphic

► More about the history and places to find oxygen.
► Next element of the periodic table.



Link to Cosmos4Kids.com Link to Biology4Kids.com Link to Chem4Kids.com Link to Geography4Kids.com Link to Physics4Kids.com Link to NumberNut.com Rader Network Side Navigation


Examples of Compounds with Oxygen

Water

This is a water molecule. Even though you find complex names on other molecules, everyone calls H2O "water". Water is made up of two hydrogen (H) atoms and one oxygen (O) atom. The formula for water is H2O. The hydrogen atoms have filled orbitals with two electrons and the oxygen atom is filled with eight electrons.

H20
Line Break
H20
Line Break
H20

Lithium Oxide

Two lithium (Li) atoms can bond with one oxygen (O) atom, making the formula Li2O. Oxygen likes to have two additional electrons to make it happy. Each lithium atom provides one. You can see that the Oxygen atom has eight electrons (6 of its own, and one from each lithium), and the two lithium atoms have two electrons each.

Li2o
Line Break
Li2O
Line Break
Li2O

Hydrogen Peroxide

Two hydrogen (H) atoms can also bond with two oxygen (O) atoms, making the formula H2O2. That's just one more oxygen than water, but it is a totally different compound. You can see that each of the Oxygen atoms has eight electrons, and the two Hydrogens have two electrons each. See how the electrons are shared?

H2O2
Line Break
H2O2
Line Break
H2O2



Related Links
- Chem4Kids: Periodic Table
- Chem4Kids: Atoms
- Chem4Kids: Compounds
- Chem4Kids: Carbon
- Chem4Kids: Nitrogen
- Chem4Kids: Chemical Bonds
- Chem4Kids: Biochemistry
- Geography4Kids: Biosphere
- Geography4Kids: Oxygen Cycle
- Biology4Kids: Cell Function

RETURN TO TOP
or
Search for more information...

* The custom search only looks at Rader's sites.

Chem4Kids Sections

Rader's Network of Science and Math Sites