The periodic table
The periodic table is a table of all the known existing elements! Some of these you may already know, such as Hydrogen, Helium, Magnesium, Iron, Oxygen, Gold, Silver and Fluoride. So far there are 118 discovered elements. They are arranged on the table by their atomic number. The rows are called periods and the columns are called groups. Each period and group have their own special properties.
A periodic table looks like this:
A periodic table looks like this:
Here is a cool way to learn the periodic table:
ATOMS AND MOLECULES
Chemists
perform their work by rearranging atoms and molecules and observing the
reaction. Atoms are teeny tiny little building blocks that make up
EVERYTHING! Even YOU are made up from
Atoms.
There are lots of different types of atoms, that come from the periodic table. You might have heard of oxygen atoms? Helium atoms (Yes, the stuff that makes your voice sound funny!) When a group of Atoms hang out together, they form a molecule! One famous example of this is a Water Molecule, aka H2O. Chemists sometimes represent molecules and atoms like this:
There are lots of different types of atoms, that come from the periodic table. You might have heard of oxygen atoms? Helium atoms (Yes, the stuff that makes your voice sound funny!) When a group of Atoms hang out together, they form a molecule! One famous example of this is a Water Molecule, aka H2O. Chemists sometimes represent molecules and atoms like this:
In a H20
molecule, there are 2 hydrogen atoms that are joined to an oxygen atom! This is
a very simple molecule. There are some molecules that are very complex and have
lots and lots of atoms in it!
When molecules join up, they form a compound.